Beer

The Origin of the “Cereal Wine”—Beer

The origin of beer lies far back in prehistory; there is evidence that it was being made at least eight thousand years ago in Mesopotamia, but it had probably been produced many different places. Its great success must be closely related to the development of cereal agriculture, which occurred about ten thousand years ago. The sequence of events might well have been:

1. Making a dough of grain (whether crushed or uncrushed), which then underwent spontaneous fermentation.
2. Baking dough into bread, soaking the bread in water, heating the result, and allowing it to cool and then to undergo spontaneous fermentation. (A similar process would have occurred if the grain had been mixed with water and boiled into porridge: after cooling, it would have undergone spontaneous fermentation.)
3. Steeping the grain induces sprouting and the synthesis of amylase enzymes that decompose the starch of the grain into sugar, a process that is aided by heated water and/or baking. After cooling in water, the spontaneous fermentation will start. Barley has the advantage of having a rather large excess of amylases in comparison with other cereals such as millets and sorghum.

When people learned to steep grain in water and then heat it slowly, the overall product was greatly improved. Another improvement to the process that was invented was to bake bread from crushed or malted grain and then immerse it in water and heat the result. If bread was the intended product, more crushed or malted grain could be added to the dough; if beer was desired, all that was needed was the addition of more water instead. It is unknown when the use of a starter (a small amount saved from a previous fermentation for use in the next fermentation) began.

All these primitive beers were, technically, ales (that is, top-fermented)—spontaneously fermented both by yeasts and by Lactobacillus, which gave the beverage a sour taste.

Domestication of Barley, Wheat, and Rye

Domestication of the most important beer cereals—barley, wheat, and rye—started at least ten thousand years ago at the transition from the Pleistocene to the Holocene period in the Fertile Crescent, the region from the eastern Mediterranean Sea to the eastern part of the Tigris and Euphrates area. When the glacial ice finally started to withdraw in the Northern Hemisphere, the climate of the Fertile Crescent was mild, wet, and ideal for early man, and numerous species of wild cereal grasses (grains) available for gathering flourished. Subsequently, the climate got warmer and drier and agriculture, a more prolific and dependable source for grains and other foods, was developed through the domestication of wild plants. The exact course of this domestication is complex, and is based in part on climatic changes, plant availability, preadaptive technology, population pressure, and resource stress.

All three cereals, barley (Hordeum), wheat (Triticum), and rye (Secale) are grasses in the tribe Triticeae, and they have all in different varieties played a great role in the development of beer in the Eurasian region. In other parts of the world, other cereals have had the corresponding importance, for example, sorghum (Sorghum bicolour) in Africa, rice (Oryx sativa) in Asia, corn or maize (Zea mays) in America, and millets. Cereals not belonging to the wheat, barley, oats, maize, or rice genera are commonly referred to as millets and are found in America, Africa, India, and Eurasia.

All domesticated varieties of barley belong to the same species, Hordeum vulgare, and its wild form H. vulgare spontaneum crosses easily with all domesticated forms. The major morphological difference between the wild and the domesticated forms is a tough rachis (the main stem holding the seed clusters) in the latter. In principle, there are three forms of barley, the two-rowed, the six-rowed, and the naked-grain form.

In connection to beer, the most important domesticated wheat varieties have been einkorn (Triticum monococcum), emmer, and the bread wheat, Triticum aestivum. Einkorn is a diploid form close to its wild ancestor, emmer is tetraploid, and the bread wheat is hexaploid.

Domesticated rye, Secale cereale, is very closely related to wild rye, Secale montanum, which still grows in the mountains of Turkey, northwestern Iran, and the Caucasus. Wild rye is more cold-and drought-resistant than are wild wheat and barley. Cultivated rye is predominantly a winter crop and it can succeed under less favorable climatic and soil conditions than can wheat.

There was probably a close connection between the production of beer and bread, the domestication of barley, and the social and ceremonial importance of the alcohol in beer. Beer was produced from bread, and barley is a very suitable cereal for both bread and beer production. Additionally, alcohol has been emphasized to have an important role in social relationship, in matters of reciprocity and obligation. The archaeologists Solomon Katz and Mary Voight have proposed that the development of settled agriculture was dependent on the desire to brew beer.

Mesopotamia

The oldest documentary evidence of beer brewing comes from Uruk in Mesopotamia and dates to about 3500 B.C.E.; it is found on clay tablets that tell the story of Gilgamesh in Sumerian, written in cuneiform with accompanying pictures. The tablets describe in great detail how beer was prepared, the different varieties of beer, how its brewing and selling was arranged, and how it was consumed. Röllig (1970) gives an excellent review of most of the details from the historic periods in Mesopotamia from the old Sumerian period (about 3000 B.C.E., which is the most interesting period for our present purposes) until about 1000 B.C.E.

At this time in Mesopotamia, barley was the most important cereal for both humans and animals. The grain was steeped into water and then either air-or oven-dried. After removal of the sprouts, the malt was milled. For brewing, various kinds of beer-breads or bappir were baked from unmalted barley or other cereals and added, along with sweeteners and spices; it has been proposed by some investigators that hops were sometimes used also. (The amount of emmer used was taken as indicative of the quality of the beer.) Then the malt and the beer-breads were probably mixed with water and heated, after which the vessel was removed from the oven to cool. It has been pointed out by Katz and Maytag (1991) that the “cooked mash” was spread out on mats to remove the spent grains and to allow the liquid to drain. By the time of the hymn to Ninkasi, from about 1800 B.C.E., a “filter” had become the symbol of the brewers. Consequently, long straws were not necessary any longer, and the beer could be consumed directly from cups. Before fermentation, spices, herbs, and sweet plant extractives with effects that were believed to be medicinal were added; the augmented sugars and microorganisms from the herbs helped to induce fermentation. (It is known that the brewers saved some of the wort from one fermentation to use it as a starter for the next brew, as has often been done in sour-bread fermentation.) Katz and Maytag (1991) also found in the hymn of Ninkasi that date juice and grapes or raisins were added to the wort to induce fermentation. The entire concoction was then transferred, with more water, into a fermentation vessel, which was long and narrow-necked to minimize the mixture of inside and outside air and decrease infection from outside. We do not know how long fermentation lasted, but probably most of the beer was quickly top-fermented into weak ale, which was tapped from the bottom of the vessel through a filter after a few days.

In early Sumerian times, beer was drunk through long straws, with the remnants of all the ingredients still present in the beer; such a straw, made of gold, has been found in a tomb at Ur. In later times, the beer was filtered as described above and then drunk from small vessels.

Many different recipes and descriptions are preserved from the Mesopotamian period: “strong beer,” “red-brown beer,” “pressed beer,” “dark beer,” and “good dark beer,” for example. These beers were very heavy and thick—almost like syrup—and very nutritious. Although they were very strong and heavy, they could not stand long storage in the warm climate, and so the people had good reason to complain about sour beer. The goddess of beer of the Sumerians was Ninkasi, who was in charge of everything concerning beer, one of the most important ingredients of life in Mesopotamia, both as a food and socially. A Sumerian proverb says: “Who does not know beer, does not know what is good. Beer makes the home pleasant.” It is interesting to note that the first very important king of Babylonia, Hammurabi, who reigned between 1792 and 1750 B.C.E., issued a set of laws (known as the Code of Hammurabi) that governed civil and criminal matters, included in which are rules for making and serving beer. (One copy of the code can be viewed on a column made of green diorite that is housed at the Louvre Museum in Paris.)

Egypt

For the ancient Egyptians also, beer was the preeminent beverage and was more popular than water, which often was contaminated; and although beer had a lower social status than wine, beer was a necessity for the household and the kitchen. Brewing was the woman’s task, as it was in Mesopotamia. The divinities presiding over it were goddesses and some kind of chief brewer (the official Kha-bau-Seker, who bore the title of “Controller of the Brewing Women”). According to Egyptian religious tradition, Osiris, the god of agriculture, taught the people to prepare beer. The Greeks connected Osiris with Dionysus, the wine god, who in turn was associated with the earlier Thracian god Sabazius. The connection between the Egyptian people, beer, and their gods—for instance, Hathor-Sekhmet—was very close. The intimate relation between baking and brewing in Egypt and in Mesopotamia is supported both by the use of the Sumero-Akkadian word lahamu, originally meaning “loaves” (compare Hebrew laham, “bread”), to indicate brewing and by the constant association of baking and brewing in Egyptian art. “Bread and beer” was the symbol of food and a greeting formula.

Artifacts dating from about five thousand years ago found in the ancient tombs of Beni Hassan in Egypt show an established practice of brewing, serving beer to the public, and exportation of beer through the city of Pelusium to many Mediterranean ports. The Book of the Dead, which dates from the same era, depicts beer being made from barley and offerings of cakes and beer to various deities.

The process of malting and dehusking the malted grain is probably thousands of years old, and the methods of today are very similar. In general, the preparation of beer, as described in late Egyptian documents and in tomb art of all periods, did not materially differ from the methods of preparing present-day bouza or its African analogues; however, Egyptian beer was often flavored by such plants as skirret (Sium sisarum—a member of the water-parsnip genus).

The Egyptians used either malts of various grains (principally emmer), which were formed into dough, or dried bread, and yeast (Saccaromyces winlocki), which was fermented in a rather warm place. In principle, there were two methods:

1. Steeping the grain in water, and then aerating it, remoistening it, grinding it, working it into a dough, and adding yeast. Finally, after fermentation, the whole mass was strained though a cloth or a sieve, and the filtrate recovered.
2. Drying bread, soaking it in water, and leaving it to ferment in a warm place, which is identical to the traditional method for making kvas (“kvass,” in English—a beer made in Russia, typically from rye).

The preparation of bouza in modern southern Egypt and the Sudan consists of the following steps:

1. Ground wheat, barley, or other cereal is kneaded with water and yeast.
2. After a short leavening, the dough is lightly baked into thick loaves.
3. Another fraction of wheat is moistened, exposed to air for some time, crushed, and then added to the previously prepared loaves after they have been crumbled.
4. The fermentation is initiated by adding some old bouza.

Flavorings are not added. The result is a thick beverage with a strong yeasty odor.

Beer was consumed primarily for pleasure and nutrition, but it was also used for cooking and for medicinal purposes, often as a constituent of mixtures. The beer given to the slaves was unfiltered and crude, but was very nutritious because it contained residual grain proteins and vitamins.

From Late Egyptian Times to the Nineteenth Century

Late Egyptian to Roman Times

The Egyptians exported beer to the Greeks, who traded it to Gaul, to Spain, and to the east coast of the Adriatic; it then spread to Germania (what is now Germany and some portions of central Europe), where it became very popular. Beer may also have been established in non-wine-producing areas at an earlier date. It is rather probable that beer production originated close to the geographic expansion of agriculture, which implies that beer could have been present in Europe at least around 3000 B.C.E., when use of the plow spread in Europe. In a female grave in Egtved in Denmark from about the year 1357 B.C.E. rests from an alcoholic beverage were found in a vessel made of birch bark. It contained rests of wheat, cranberry, honey, and bog myrtle (sweet gale). (Corresponding remains have been found in the Hallstatt beer amphora found at Kulmbach dated 800 B.C.E.).

In China, alcoholic beverages seem to have been present since 4000 B.C.E. in Dawenkou in Shandong; the oldest written documents come from the Shang dynasty, 1324-1066 B.C.E., written by Du Kang and describing the production of jiu. Jiu meant all alcoholic beverages, usually of 10-15 percent alcohol, obtained by fermentation of cereals, millet, and wheat. The process was first to make a ferment cake, which provided molds and yeasts that then started the fermentation process in a mash of cooked cereals. During the T’ang dynasty, 618-907 C.E., the cereals for this process were either glutinous millet or glutinous rice. These processes later spread to Japan, Korea, and all of Southeast Asia. Prior to the introduction of this process in Japan, brewers saccharified the rice by chewing boiled and raw rice.

Beer was a considered a barbaric drink by the Greeks and Romans, though, according to Pliny, beer was known in the Mediterranean countries before viticulture (the cultivation of grapes) became popular. There are frequent references—in Tacitus, for example—early in the common era to malt beverages being consumed by the tribes of Germania (as well as by the Saxons, Celts, Thracians, and Scythians), and even to the establishment of tabernae, or taverns. Originally, beer was produced from a variety of malted and unmalted grains such as millet, barley, wheat, oat, and rye, with different supplements such as honey, juniper, mushrooms, and bark—but without hops. In the Greek and Roman world, wine was the beverage of the upper classes and beer was the drink of the common people, as was the situation in pre-Ptolemaic Egypt. (For more details see Arnold [1911] and Hoffman [1956].)

Medieval Times to the End of the Nineteenth Century

Home brewing

From the year 719, when the Lex Alemannorum (a code of laws formulated by the Franks) was promulgated, all people in the Germanic area were entitled to brew their own beer. Home brewing began in Great Britain in about the twelfth century. With the growth of towns, commercial operations started brewing and selling in the same establishment. Later, the point of sale was centrally located in a town or city. Growth of brewing was slow until the industrial revolution made large breweries possible.

The types of beer and brewing techniques of the Middle Ages survived until recent years in the Nordic countries, as has the old method of spontaneous lactic and alcoholic fermentation of kvas (“kvass,” in English—a beer made typically from rye) in eastern Europe.

Monasteries

Monasteries have had an active role in the brewing and sale of beer, and in the improvement of brewing processes. Two of the first beer-brewing monasteries—with brewing activities dating back to the seventh to eighth centuries—were St. Gallen (in Switzerland) and Weihenstephan (in Bavaria), both of the Benedictine order. Beer was a substitute for wine, a good nutrient during Lent, and an excellent base for spices used medicinally. In the year 1000, forty of the houses of the monastery of St. Gallen were devoted to brewing; they produced strong beer, oat beer, and light beer for themselves, guests, and pilgrims, and for sale. In the early Middle Ages, there were four to five hundred monasteries brewing beer in Germany; the practice was international and a large source of income for the monasteries. The famous Trappist beer is still made in Belgium by Trappist monks, whose order has developed from the Benedictine and Cistercian orders.

Cities

In southern Germany, Bavaria was a wine-drinking area until the Thirty Years’ War (1618-1648), and the monasteries were the main producers of beer. During the twelfth and thirteenth centuries, cities were burgeoning and they created licenses to produce beer, which could be heavily taxed by the authorities. In the northern part of Germany, many competing breweries were developed and great volumes of beer were exported by members of the Hanseatic League to other parts of Europe. In the northern city of Hamburg, there were six hundred brewers in the sixteenth century, as contrasted with only thirty in the southern city of Munich in the fifteenth century. Some of the most famous breweries in the sixteenth century were in Erfurt, Einbeck, Zerbst, Naumburg, and Braunschweig.

After the Thirty Years’ War, which destroyed the northern cities and Bavarian viticulture, most of the brewing shifted from the north to Bavaria, where by 1420 the monasteries had developed the method of bottom fermentation that produces lager beer. Before this development, all beers were top-fermented—that is, ales. In 1516 the Reinheitsgebot (Purity Law) was approved for Bavaria, which decreed that only barley malt, hops, and water were allowed for beer brewing. In 1551 another law was approved in Munich saying that bottom-fermenting yeast should be used. Northern Germany was opposed to the new law, and Baden and Württemberg did not accept it until 1896 and 1900, respectively. In 1906 it was accepted for lager throughout the German Empire. The only exception made was to allow wheat malt in the specialty ales Alt, Kölsch, and Berliner Weisse and in wheat beer.

Grut and hops

Ancient beer was flavored by many different spices, even medically active ones, during the centuries, and Hildegard von Bingen mentions in her Physica, which dates from about 1156, both hops and grut as additives to beer, which is the first documentation of the use of hops in beer. Grut was a mixture of several spices, chief among them being the leaves of bog myrtle or sweet gale (Myrica gale). It was used mainly during the thirteenth to fifteenth centuries and it survived in the northwestern part of Germany and in the Netherlands until the eighteenth century. In many areas, the authorities sold the right to use grut (Grutrecht). During these times, hops and grut were used for beer simultaneously.

Hops had been introduced for beer brewing sometime between the years 764 and 1156, when the first hop agriculture was found in Geisenfeld in the Allertau area in Bavaria, and when Hildegard wrote her Physica, respectively. The introduction of hops probably came via contacts of the Germans with Slavic peoples in central Europe. The acceptance of hops in beer was very slow and even forbidden in certain areas. By the year 1400, the Dutch had already introduced hops, but it was not until the sixteenth century that the use of hops in beer was gradually accepted in England. One reason for this slow acceptance could have been the difference in taste of the beer, from a rather strong and sweet beer without hops to a less strong and somewhat bitter beer. The great advantage of hopped beer was the better storage capabilities it afforded.

Ale and lager

Ales were the only beer type in Europe before the advent of lager, beginning in the fifteenth century in Bavaria. In 1603 lager was forbidden by the city of Cologne. However, it slowly spread through Germany together with the Purity Law, and during the nineteenth century, production volume increased dramatically. The most important types of lager were the dark from Munich, the pale from Dortmund, and the pale and heavily hopped from Pilsen (pilsner). Dortmund Export became world-famous in the nineteenth century, and pilsner became the great winner in the world of the twentieth century. In the northern and western parts of Germany, ales dominated until the start of the twentieth century.

In England, Professor Charles Graham became interested in lager in 1888 and started a discussion about the two types of beer. It was not until the end of World War II that lager was accepted by the British people. One significant impediment to the success and spread of lagers was their great need for cooling.

In Britain, ales have been the popular beers and have influenced tastes in both British colonies and other countries through export. At the end of the seventeenth century, most of the export of ale from Britain went to America and the West Indies, but the trade of strong, sweet ale, “Russian Imperial Stout,” and porter (a heavy, dark-brown ale) to Russia and the countries around the Baltic had begun. In the beginning of the nineteenth century, half of the ale exported by Britain went to Asia and Australia. That type was called Indian Pale Ale (IPA); it was strong, sweet, and highly hopped.

Development in America

Brewing in America started with the early British and Dutch settlers. As early as 1587, Sir Walter Raleigh malted maize (corn) for brewing, and hops were grown by 1637 in Charlestown, Massachusetts. Malt and ale were imported from Britain, and New York and Philadelphia became the main brewing centers in the eighteenth century. In Canada, brewing was initiated in 1620 by the monastery of Notre Dame des Anges. The first steam engine was installed in Philadelphia in 1819. At the beginning of the nineteenth century, there were 150 breweries in the United States, producing 160 thousand Imperial barrels (7.2 million U.S. gallons).

From 1840 onward, German immigrants began brewing lager, and the number of breweries increased to 4,131 in 1873; this number decreased to 1,092 in 1918 and 230 in 1961. In 1850, ale brewing was dominant, and in 1860, lager production was less than twenty-five percent of the total production of 3.8 million barrels. Hop culture spread to California in 1851, Wisconsin in 1860, Washington State in 1866, and Oregon in 1880. After 1850, lager began to prevail, but brewing it required ice, and machines to make that ice. This requirement was met by the introduction of the refrigerator. The first one was installed in New Orleans in 1867.

Brewing companies and the science of brewing

By the beginning of the eighteenth-century, three items had been invented that later had very great importance for the brewing industry: the hydrometer, the thermometer, and the steam engine. Both the hydrometer (along with its offshoot, the saccharometer) and the thermometer gave the brewer instruments to measure and monitor processes more exactly, and the steam engine—which replaced horses—opened possibilities of working with greater volumes in the brewery. All the vessels of the brewery were still of wood except the brew kettle, which was made of copper. The technical revolution during the eighteenth and nineteenth centuries, as well as the beginning of free trade among both cities and states, had a great impact on the development of the brewing industries in Europe and the United States, and it was during this time that most of the big brewing companies were started and formed.

However, the most important inventions for the breweries were made in the biological and biochemical fields. In 1833 Anselme Payen and Jean-François Persoz discovered an enzyme, diastase, that can split starch. In the late 1830s, Franz Schulze discovered the yeast cells, Saccaromyces; his discovery was confirmed by Louis Pasteur in 1857. The final synthesis explicating the fermentation process was performed by Eduard Buchner in 1897; he demonstrated that fermentation could proceed with just the juices of the yeast cells—without the living cells—showing that a complex of enzymes (zymase) is responsible for the conversion of carbohydrates to alcohol and carbon dioxide.

Before these discoveries, people did not know why and how fermentation occurred. Often they ascribed it to supernatural forces, and many used the same equipment from fermentation to fermentation; sometimes sourdough from bread baking was used to initiate the fermentation. In any case, most of these beers and ales were also lactic-fermented and thus sour. In 1883, E. C. Hansen from the Carlsberg Laboratories of Carlsberg Brewery in Copenhagen isolated the active yeast culture from bottom-fermentation yeast, which J. C. Jacobsen, the founder of the brewery, had brought there from Munich. This species was called Saccaromyces carlsbergensis (it was later renamed Saccaromyces ovum) and today is considered a variety of Saccaromyces cerevisiae, the common yeast organism. Jacobsen’s method of isolation and pure-culture propagation of yeasts from single cells was rapidly adopted. By 1896 it was in wide use in lager breweries in many countries and has become the standard method.

Germany became unified during the nineteenth century, and it was then possible for breweries to sell their products over a wider area than before. The first limited brewing company was formed in Dresden in 1838. Between 1831 and 1865, because of the great success of lager, there was a dramatic fall in the numbers of breweries producing ales in Prussia, from 16,000 to 7,400. The first scientific brewing research institutions were formed in Bavaria (Munich and Weihenstephan) in 1880, and in Berlin in 1883.

The Twentieth Century

Beer in 1900

The central area for modern beer development and beer culture is the portion of Europe from Austria in the southeast to the British Isles in the northwest. The Nordic nations are also beer countries, but, with the exception of Denmark, they have not played a significant role. At the beginning of the twentieth century, ales dominated the market in the United Kingdom, the northern and western part of Germany, and Belgium. Lager had started its spread from Bavaria to the big cities in Germany and to the neighboring countries. It had also become rather well established in the United States, but the populace of the United Kingdom had not yet accepted it.

Beer around the World

Around the world, Australia got Foster’s beer, a lager, from the United States in 1888. East Africa received beer from the United Kingdom in 1922, and today, lager, ale, and sorghum beer are all brewed by African breweries. One of the best-known beers from that region is Tusker lager from Kenya. Guinness and Heineken also have large breweries in the area. In South Africa, lager is dominant. In 1904, China got its first lager, Tsingtao, and in 1916 the company was acquired by the Dai Nippon Beer Company in Japan. The Japanese then spread the beer-brewing culture to other parts of East Asia.

Beer in the United States

The United States—where the brewing industry was well established before 1900, with a very wide production of different kinds of beers such as ales, stouts, and lagers—experienced a golden age of brewing between about 1870 and 1919. This, however, came to a halt on January 16, 1919, when the Eighteenth Amendment to the United States Constitution, which prohibited all alcoholic beverages, was ratified. Prohibition lasted from January 16, 1920, to December 5, 1933, when its repeal by the Twenty-first Amendment took effect. During this period, breweries had to survive on nonalcoholic products such as near beers, malted milk, ice cream, and so forth. Two of the surviving companies, Anheuser-Busch and Miller, ended up being two of the top three breweries of the world. The top ten breweries produced about one-third of the world production of 1.25 billion hectoliters (hL, equivalent to 33 billion gallons) in 1995.

World Production

During the twentieth century, world beer production increased from about 250 million hL (6.6 billion gallons) in 1900 to about 1.306 billion hL (34.5 billion gallons) in 1998, an increase of 522 percent. In 1900, production volumes in Germany and the United States were about equal and together constituted about half of the world production. In 1998, the United States produced 238 million hL (6.29 billion gallons) and Germany 112 million hL (2.96 billion gallons), which together represents only 27 percent of the world production. World production of beer was distributed by region in 1997 as follows: the Americas, 37%; Europe, 34%; the Far East, 23%; Africa, 4.5%; the South Pacific, 1.8%; and the Near East, 0.1%. The greatest increase in beer production is found in areas far away from the traditional beer countries—such as China, countries in Latin America, South Africa, and Turkey (an Islamic country). It is evident that they have evolved a new way of life. Two of the traditional beer countries, Germany and the United Kingdom, are still in the top ten in production, but they will probably soon be overtaken by some of the countries mentioned above.

World Per Capita Consumption

Per capita consumption of beer in different countries shows which people have beer as their natural and central beverage. The top ten countries in 1999, each with a per annum consumption of at least 88.1 liters (23.3 gallons) per person, are still from the old beer center of Europe, which stretches from the British Isles to Austria and up to Denmark (Table 1)—except for Australia, which got its beer traditions from the British colonization of the continent. The newcomers are Turkey, some Latin

American countries, South Africa, and several European countries (including some that have traditionally been considered “wine countries”). Except for the Czech Republic, the Republic of Ireland, and Austria, the traditional beer countries show a decrease in per capita consumption (Table 1).

Lager and Ale

During the twentieth century, a variant of pale lager, pilsner, became the big winner all over the world—in Australia, the United States, and even the old ale area of the British Isles. Only northwestern Europe is bucking the trend: In Belgium, Trappist-Abbey and brown ales are increasing in production, as are Altbier, Kölsch, and wheat beer in Germany. In the British Isles, bitter ale, pale ale, mild ale, Scotch ale, sweet stout, and barley wine are decreasing in consumption; only bitter stout is increasing. Consumption of draft beer in Great Britain for 1999 is as follows: lager, 44.8 percent; ale, 42.2 percent; stout, 6.3 percent. The remaining 6.7 percent of the total consumption concerns packaged beer of all types. It was not until after World War II that lager truly began to succeed in Great Britain, and it took about fifty years for it to achieve approximately 50 percent of the British market.

Beer Developments in the Twentieth Century

Characteristic of the development of beers and breweries during the twentieth century is the worldwide success of the American variant of the Bohemian lager, pilsner—crystal-clear pale-dry beer, often of the light type, with a low taste of malt and a low bitterness, frequently served very cold. Another trend is that the number of breweries has decreased, individual breweries have become bigger and bigger, and different companies have merged into great brewing conglomerates. In the United States, there were 750 brewing companies and plants in 1936; this number had decreased to 26 companies and 215 plants in 1989, despite a 440 percent increase in volume. Still another trend is the increase of popularity and consumption of beer in nontraditional beer-drinking areas such as Latin America, South Africa, and various parts of Asia. The exportation of beer is a huge worldwide business; Table 2 lists volumes for countries with large exports and imports.

The establishment of microbreweries, which started in 1981 and had increased to 500 breweries by 1992 in the United States, and has spread to other countries as well, is an interesting development that demonstrates the desire for high quality and diversity of beer. Other important developments are ice beer (made by freezing off some of the water); dry beer, with a very low content of residual sugar; light beer, with a low content of dextrins in the beer; low-alcohol beer (less than 1.5 percent alcohol by volume); and nonalcoholic beer (less than 0.5 percent alcohol by volume). Most important are the advances in biochemistry, which have allowed brewing to become an industry based on science and technology. The industry has progressed to the use of stainless steel vessels and containers, and all processes are fully automated and all by-products are taken care of. The expenses for beer production are dominated by costs for packaging, sales, production, and taxes; only a very small proportion of the costs is needed for raw materials.

Beer and Health

Calories, vitamins, and minerals

The effects on health of beer drinking depend to a large degree on which beer is consumed, how much, and by whom. Contents of alcohol, carbohydrates, and proteins differ greatly between low-and high-alcoholic beer. The nutritional value of heavy beer is significant, especially if the beer is unfiltered and contains yeast cells. The caloric value of beers varies from 276 kcal/L in alcohol-free beer, to 428 kcal/L in pilsner, to 660 kcal/L in a Doppelbock (double-strength bock beer—a heavy dark beer). For example, 360 ml (just over 12 fluid ounces) of ordinary beer with 419 kcal/L, 4.5% alcohol and 38 g/L carbohydrates will give about 5-12% of the Recommended Dietary Allowance (RDA) of folate, niacin, vitamin B6 (pyridoxine), riboflavin, and pantothenic acid; 10.3% RDA of magnesium; and 13.5% RDA of phosphorus. Thiamine and pantothenic acid amounts are rather low in beer in relation to the caloric content. This implies that other dietary sources of B-complex vitamins are needed. Beer also contains some chromium, which is needed for glucose and lipid metabolism. The amount of chromium present can be significant for chromium-deficient people. Further, the low content of sodium tends to counteract the water retention seen in heavy drinkers, which, in fact, may typically result from their additional salty food intake. Aside from the caloric content of modern filtered beer, it cannot be regarded as an important nutrient, since the vitamin and mineral contents are relatively low, but it does make a contribution. To make a complete meal with beer, a source of protein and fiber-rich vegetables should accompany the beer.

Medical effects of beer

Although beer is a low-alcoholic beverage of less than 10% alcohol by volume (typically about 5 to 7 percent) in comparison with wine and spirits (about 10 to 50 percent), all the effects of alcohol must be considered. For reviews on this subject, see Cox and Huang (1991, 165-176) and Owades (2000, 19-26). Generally, beer has not been found to differ specifically in its physiological effects on a short-or long-term basis from other alcoholic beverages, if the effects are related to the amount of alcohol consumed. Beer also has the advantage of filling the stomach more quickly than wine and spirits and will give a slower increase of blood alcohol level. Heavy drinking may provoke diarrhea or vomiting and cause excessive urination, all of which flush vitamins and minerals out of the body. Heavy drinkers of alcohol may get dilated cardiomyopathy with specific intracellular changes, which is a kind of congestive heart failure. In 1884, it was described as Münchener Bierherz (Munich beer-heart) by Bollinger. This type of disease also occurred during the period of addition of cobalt to beer to stabilize its head.

In the past, alcohol has, in the medical literature, usually been connected to negative and hazardous effects on the body; however, in recent decades, a large number of clinical studies have shown that moderate drinking (about two to three drinks or twenty-five to eighty grams [about 0.88 to 2.8 ounces] of alcohol per day) decreases the risk for cardiovascular morbidity and mortality in comparison with both a higher and a lower alcoholic consumption, and most studies indicate that there are no beneficial differences among alcoholic beverages (but see below). Subjective health has also been shown to be highest in persons with a moderate alcoholic consumption (100 to 199 grams [about 3.5 to 7.0 ounces] per week). The beneficial effects of alcohol might be explained by an increase of HDL-C (high-density lipoprotein-C), decreased levels of prothrombotic factors such as fibrinogen, and reduced platelet aggregability, vessel contractility, and pulmonary artery pressure in heart failure patients. Antioxidative compounds—which may decrease the oxidation of LDL (low-density lipoprotein) and the risk for atherosclerosis—such as polyphenols, gallic acid, rutin, epicatechin, and quercetin in red wine and in full-bodied and darker beers may have additional beneficial effects. The question of whether some alcoholic beverages have more prominent effects in these respects remains to be elucidated in further clinical studies. However, red wine has been proposed to be more efficient than other alcoholic beverages in a number of studies.

Hops and medical effects

Other effects of beer, such as the central nervous arousal and the sedative effects, can be explained by the general effects of alcohol. It has often been discussed whether compounds from hops might influence the physiological effects of beer. It is interesting to note that hops—dried, liquid extract, and tincture—are recommended by health-food specialists for various conditions: “Hops are stated to possess sedative, hypnotic, and topical bactericidal properties. Traditionally, they have been used for neuralgia, insomnia, excitability, priapism, mucous colitis, topically for crural ulcers, and specifically for restlessness associated with nervous tension headache and/or indigestion.” (Newall, Anderson, and Phillipson 1996, 162-163). Antibacterial activity toward gram-positive bacteria is documented, but the sedative effect needs to be documented, as most of the studies are made with hops in combination with other herbs. Recurring suggestion has been made that hops and beer have estrogenic activity and that the infection of molds producing estrogenic mycotoxins is a significant problem. Recently, a potent phytoestrogen, 8-prenylnarigenin, has been identified in hops and shown to have a concentration in beer of about 100m/L, which is equivalent to a few mg/L estradiol or less. This concentration in beer is not considered to be detrimental, but handling and ingestion of hops might have estrogenic effects in humans. It is also possible that 8-prenylnaringin might contribute to the health-beneficial effects of moderate beer consumption.

Production and Social Use

Beer may be defined as a cereal wine: an alcohol-fermented (and sometimes concomitantly lactic-acid-fermented) beverage, produced from one or more malted cereals, such as barley, wheat, rye, oats, corn, or rice, or from mixtures of these and unmalted cereals. In the following, the product is called “beer” if barley is at least one of the main constituents of the malt; otherwise, it is called “wheat beer,” “rye beer,” “oat beer,” etc., as appropriate.

The Basic Beer-Production Process

To ferment the starch inside the grains of the cereals, it is malted (softened by soaking in water and allowed to germinate) and mashed with warm water; this allows the diastases of the grains, which are activated by the malting and mashing processes, to break the starches into shorter carbohydrates, upon which yeasts can act. After separation, a clarified liquid, known as wort, is produced, which is then boiled with hops; this adds a note of bitterness to the beer’s flavor while killing microorganisms. After chilling, yeast is added (either naturally from the environment or as an intentional addition), and fermentation takes place. After clarifying and storage, the beer is ready for consumption.

Classification of Beers

Beers can be categorized according to the type of cereal used, but it is more common to use the type of fermentation for this purpose: spontaneous fermentation, top fermentation, or bottom fermentation.

Spontaneous fermentation

Spontaneously fermented beers are produced without the active addition of any microorganisms to the wort. The microorganisms come from the surrounding air and the equipment used in the brewing process and are a mixture of yeast species and lactic-acid bacteria, a mixture that produces alcohols and lactic and other organic acids, and gives the product a sour taste. Examples are the Russian beverage kvass, which is typically made of rye, and Belgian Lambic beer and the old Berliner Weisse, which are both produced partly from wheat. All beers made before the introduction and knowledge of pure yeast cultures were in a sense made via spontaneous fermentation. However, most such beers (as well as wines) were made inside containers that were repeatedly used for this purpose. Such containers rapidly become infected with spores that continue to maintain the original species of yeast—that is, the ones that produced fermentation in the first place. The use of the same vessel and associated equipment from one batch to the next causes the cereal grains employed to continue to be cross-infected between brewings. Recent scientific studies indicate that these spores remain alive for decades, or even longer. Moreover, many beer-making traditions include the step of adding fruit, such as raisins, to the mixture; this practice assures that the yeasts that naturally reside on the surface of the fruit will become a significant part of the microorganisms that infect the mixture.

These types of beer are technically ales—that is, they are all top-fermented.

Top fermentation: ales

Top-fermented beers, ales, are fermented at a rather high temperature, about 64-72°F (18-22°C), letting the yeast float on the surface of the wort.

Typical ales are British and Irish pale ales, bitters, stouts, and porters; Belgian ales, such as Trappist and abbey beers; and western German ales, such as Alt Bier and Kölsch. The Bavarian wheat beers—Weissbier (Weizenbier)—are also top-fermented and are produced in different varieties: pale and dark, with and without yeasts remaining, and as bock and Doppelbock. Some of the British and Belgian ales can be very strong, up to about 12-17 percent alcohol by volume, while common ales have a concentration of 3.5-6.0 percent alcohol by volume. Ales were predominant before the great expansion in popularity of bottom-fermented beers, the lagers, in the nineteenth century.

It should be noted that the term “ale” has also been used to signify unhopped beer, as contrasted with hopped beer (Cantrell, p. 619).

Bottom fermentation: lagers

Bottom-fermented beers, lagers, originated in Bavaria, where a cold-adapted yeast strain had been developed over a period of many years in the cold caves used for fermentation and storage. A temperature of about 45-59°F (7-15°C) is typical for bottom fermentation. The cold fermentation and the location of the yeast cells at the bottom of the container yield better storage capabilities and a cleaner, more purely malty taste in lagers, in comparison with ales, which are usually more fruity and bloomy in flavor. The name “lager” implies it is stored in cold conditions. Lagers are the dominating beers of the world today: pilsner; Bavarian; Vienna; Münchener, pale and dark; Dortmunder; bock; and Doppelbock beers. The difference between them depends principally on the brewing liquid, the type of hops, and the type of malt used. Bock and Doppelbock beers have a higher alcoholic content, 6.0-7.0 percent by volume and 6.0-8.0 percent by volume, respectively, in comparison with the other lagers, 3.8-6.0 percent by volume. Bocks and Doppelbocks are spring beers; their high levels of alcohol were originally produced to compensate for Lenten fasting.

Raw Materials

Barley

Barley is a grass of the genus Hordeum and of the family Gramineae; it is one of the most important cereals of the world, after wheat, maize (corn), and rice. Barley is mainly used for livestock feed and for beer malting. The world production for 1999 was 130 million tons, with the greatest producers being Germany (13.3 million tons) and Canada (13.2 million tons) (FAO, Production Yearbook, 1999). Barley is produced all over the world up to 70°N latitude; it prefers reliable rainfall, a long growing season, and deep rich soils, but it can stand much more difficult conditions. It is not as cold-resistant as wheat, and in some regions it is sown in the autumn (Kendall, pp. 109-111).

For malt production, the two-rowed form of barley is often preferred over the six-rowed, although both give excellent malts. The advantages of barley for malting are principally the following:

• The husk gives each individual grain of barley microbiological protection during malting, thereby helping to prevent the growth of mold.
• The husk provides a useful filter during traditional wort separation. The filtered material, spent grains (trub), is composed of husks, proteins, a little starch, and minerals. The trub is used for animal food (Narziss, 1995, p. 176).
• The gelatinization temperature of malt starch is lower than the inactivation temperature for -amylase, which is one of the main enzymes breaking down the starch into shorter carbohydrates. (Gelatinization accelerates the transformation to sugars and makes it more thoroughgoing.) (MacLeod, pp. 50-51)

For more detailed reviews see Hough, Briggs, and Stevens (1971) and Adamic (1977).

Water

The different composition of natural brewing water, or production water, from Pilsen, the Czech Republic; Burton upon Trent, England; Munich; Dortmund, Germany; and Vienna characterizes five types of different beers. Pilsen water has low concentrations of ions and is suitable for highly hopped lager beers with pale malt. Burton upon Trent water has high concentrations of calcium, bicarbonate, and particularly sulfate, and this combination has been shown to be perfect for highly hopped ales with dark malt. The waters from Munich, Dortmund, and Vienna have rather high concentrations of alkaline ions, and Dortmund water in particular has rather high concentrations of calcium and sulfate. Vienna water is more highly mineralized than Munich water, with a rather low sulfate but a higher bicarbonate concentration. The waters from Munich and Vienna give a lager that is not heavily hopped and is used with both light and dark malts. The Dortmunder lager is more highly hopped and has a slightly higher alcohol content and a pale malt.

Brewing water must be of potable-water quality. The ion composition and pH can be adjusted by ion exchanges, for example. The pH before wort boiling should be 5.4, so as to obtain a pH after boiling of 5.2 (Moll, pp. 138-139). The different ions of the brewing water have profound effects on the malting and brewing processes, the fermentation, the flavor, and, as a result, the type and quality of the beer. The previously mentioned famous beers are distinguished by the effects of geological conditions of their wells on the brewing water. The important cations are calcium, magnesium, sodium, potassium, iron, manganese, and trace metals. The anions are carbonate, sulfate, chloride, nitrate and nitrite, phosphate, silicate, and fluoride. Their concentrations in the brewing water should comply with those found in water suitable for drinking (for standards, see Moll, pp. 134-135).

Some of the many effects of the ions are pH adjustments made by calcium, magnesium, carbonates, and sulfate from the brewing water and phosphate and organic acids from the malting. If calcium chloride is added, insoluble calcium carbonate, phosphate, and free hydrogen ions will form, which will decrease the pH. In contrast, pH can be increased when the brew is boiled, forming carbon dioxide from carbonate and hydrogen carbonate, which binds hydrogen ions. Many of the different anions such as carbonates, phosphates, and all the organic acids in the brew have buffering capacities (they minimize changes in the pH).

Besides these pH effects, many of the cations, including trace metals, work as coenzymes for many different enzyme systems. For example, magnesium is a cofactor in the metabolic enzymes necessary to produce alcohol and protect yeast cells by preventing increases in cell membrane permeability elicited by ethanol and temperature-induced stress. Other critical trace element cofactors are cobalt and chromium, which enhance the kinetics of alcohol fermentation.

Calcium, along with phosphates, provides thermal protection for mash enzymes and is the principal factor for pH adjustments during wort boiling. It also tends to inhibit color formation during the boil, and facilitates protein coagulation, oxalate sedimentation, yeast flocculation, and beer clarification. Magnesium works similarly to calcium and causes harsh bitterness (Fix, p. 5). Sodium, together with chloride, causes a salty taste in higher concentrations (400 mg/l), but in lower concentrations it can be used to increase the “mouthfullness.” Sodium is also very important for sodium/potassium transport across cell membranes. The amount of potassium should not be excessive as it inhibits many enzymes in the wort preparation. Iron should be avoided as it inhibits the malting, gives color to the wort, decreases the “mouthfullness,” and causes a bitter taste. Iron is essential for the oxidative processes of the yeasts, especially terminal oxidation. Manganese works as a coenzyme in many enzyme systems and stimulates cell division and protein generation.

Sulfate, with calcium and magnesium, decreases the pH and stimulates the carboxyl and amino peptidases. The sulfate concentration in the brewing water determines the concentration of sulfate in the final beer (malt and hops also contribute to the amount of sulfate) but does not increase the amount of sulfur dioxide. Sulfate also increases the flower flavor of hops and gives beer a dry, bitter taste. Chloride stimulates -amylases and gives a soft and full beer taste as calcium chloride. Often, the chloride/sulfate concentration ratio is used to describe the ratio of body and fullness in relation to dryness.

Nitrates and nitrites are the last stage in the oxidation of organic material and give beer a bad taste. Nitrites are toxic for the yeast cells. Phosphate ions in the brewing water are not acceptable because they indicate organic contamination. Silicates of calcium and magnesium have negative effects on the proteins and cause protein-unstable beers. Fluorides have no negative effects on the fermentation but cause the beer to become a little darker and have a broader taste (Narziss, 1992, pp. 17-52). For more details about the effects of the ions in brewing water, see Narziss, 1992; MacLeod; and Moll.

Hops

The cultivated hop plant, Humulus lupulus, with its relatives H. japonicus and H. yunnanensis, belongs, along with species of the genus Cannabis (e.g., C. sativa, hemp), to the family Cannabinaceae. Together with the nettle family, Urticaceae, they form the order Urticales. Hops are dioecious (i.e., there are individual male and female plants) and perennial and are indigenous throughout much of the Northern Hemisphere between 35° and 70° N, though mostly cultivated today between 43° and 54° N, and 37° and 43° S. The most important regions for hop cultivation are in South Africa, Australia, Argentina, the United States, Germany, the Czech Republic, and England, having an amount of daylight during the growing season of 15:27-18:42 hours, a mean temperature of about 50-66°F (10-19°C), and average rainfall of between 2.5 and 22.4 inches during the period of April to September in the Northern Hemisphere and October to March in the Southern Hemisphere (Barth, Klinke, and Schmidt, p. 49). The world production in 1999 was about 98,000 tons, with Germany contributing about 28,000 tons, the United States about 29,000 tons, and China about 15,000 tons (FAO, Production Yearbook, 1999). Many different varieties of hops with different contents of humulone (an antibiotic) and hop oils have been developed, particularly in Germany, England, and the Czech Republic. (For more details about the varieties, the history, and the trade, see Barth, Klinke, and Schmidt, pp. 1-383.)

Both pollinated and unpollinated cones (strobili) from the female plants are used, with the unpollinated ones used in Germany thought by some to yield a better taste than the seed (MacLeod, p. 80). Inside the infolded bases of the bracteoles (the small leaves from which the flowers grow) and on the seed are the resin-producing lupulin glands, which contain the essential compounds for use in beer: the resins humulone (the -acids) and lupulone (the -acids), and the aromatic hop oils. The -acids yield, after boiling and isomerization, iso-α-acids, which contribute bitterness to the beer, and hop oils, which contribute to the aroma. In addition, hops also benefit beer by improving clarity and foam stability, and, most important, flavor stability because of bacteriostatic activity of the iso-α-acids (flavonoids) (Grant, pp. 157-167). Hops are the major preservative of beer.

Other herbs and spices

Down through history many types of herbs and spices have been added to beer (von Hofsten, pp. 208-221; Rätsch, pp. 28-40), and many of them have been considered to be remedies. Besides hops, sweet gale (Myrica gale) and marsh tea (Ledum palustre), two of the constituents of the old European mixture of beer additives, grut, are believed to have been in widespread use. Placotomus mentions in his book from 1543 the use of more than twenty plants as additives for beer (von Hofsten, p. 212).

Since 1516, when the Reinheitgebot (Purity Law) was approved in Bavaria, the use of additives other than hops in beer has been prohibited there; this inhibited the use of new herbs and spices, and new combinations of old ones, in beer in Bavaria. However, in Belgium and its surrounding areas, and in Great Britain, other types of beers using wheat and herbs and spices were developed. Many of the recipes are secret, but we know of the use of coriander leaves and seeds, cardamom, camomile, clover, grains of paradise (the seeds of the West African plant Aframomum melegueta), cinnamon, plums, peaches, cherries, coffee, chilies, and chocolate (Jackson, 1998, pp. 16-17).

Yeast

The living microorganism producing beer from wort by anaerobic degradation of sugars to alcohol is a yeast species, Saccaromyces cerevisiae, which is also used for baking and wine fermentation. The species has at least a thousand different strains (Barnett, Payne, and Yarrow, pp. 595-597). Two of them are S. cerevisiae cerevisiae used for top-fermentation of ales and S. cerevisiae uvarum (carlsbergensis) used for bottom-fermentation of lagers. They differ from each other by the temperature used: as noted above, 64-72°F (18-22°C) for the ales and about 45-59°F (7-15°C) for the lagers. Further, S. c. uvarum (carlsbergensis) has the ability to ferment the disaccharide melibiose, which S. c. cerevisiae is unable to do, due to lack of the enzyme melibiase (galacoidase) (Russel, pp. 169-170). Different breweries have developed their own strains or mixtures of strains of yeast to maintain the distinctive qualities of their beers. Important requirements for a good brewing yeast are flocculating power (i.e., the capability of forming loose, fluffy clumps), ability to ferment maltotriose (a complex sugar found in the wort), head-forming potential, fermentation efficacy, interaction with isohumulones (forms of the antibiotic -acids produced by hops), response to fining (clarifying and purifying), and propensity for producing important individual flavor components (MacLeod, p. 84). In the San Francisco beer Anchor Steam, lager yeast is used for fermentation at a high ale-fermentation temperature, which gives a very interesting beer with the roundness and cleanness of a lager and the fruitiness and some of the complexity of an ale.

Outline of Modern Brewing Procedures

Detailed descriptions of this highly technological and scientifically based process can be found in de Clerck (1957-1958); MacLeod (1977); Hardwick (Handbook of Brewing, An outline of the different procedures is given by Hardwick (“An Overview of Beer Making,” 1995, p. 88).

Beer Chemistry

Malting

The process of malting grain starts with steeping it in water. After several hours, the embryo begins to take up water and to grow. To produce energy, the growth hormone giberellinic acid is formed and transported to the aleurone cells around the starch-rich endosperm to start the formation of hydrolytic enzymes such as -amylase, endo-β-glucanase, and peptidase. The cell walls of the endosperm contain -linked glucan and pentosan, which are degraded by the endo-β-glucanase and pentosanases. The net action is to solubilize and break down the cell walls and the small starch granules in the endosperm. The peptidases break down the peptides into amino acids, which are essential for yeast nutrition; the large polypeptides, which have not been used by the yeast cells during fermentation, are important for foam stability in the final beer, but in conjunction with polyphenols have the potential to form undesirable haze in the beer.

When the malting is completed, the malt has to be kiln-dried to stop the enzymatic activities and to reduce the water content so as to allow storage of the finished malt. The kilning is divided into two steps: the drying, at temperatures up to 176°F (80°C), giving a moisture content of 4 percent; and the curing process, at higher temperatures, yielding flavor components through the Maillard reaction. This reaction browns the malt, producing amino acid-carbonyl compounds, which undergo further transformations to yield the colored, aromatic compounds known as melanoidins. The higher the temperature, the darker the malt will be and the more the enzymes will be inhibited (Kendall, pp. 117-118; Fix, pp. 41-45). These compounds contribute both to dark color and to different varieties of burnt-sugar or caramel taste. The malt type and the mixture of malts forms the body or the “mouthfullness” of the beer and produces the basis of classification into pale, medium, and dark beers. If the malt is kilned over an open fire, it will acquire a definite smoky taste like the Bavarian Rauchbier, “smoke beer.” The feeling of “mouthfullness” can be decreased by splitting the residual sugar of the beer, the -glucans, dextrins, by exogenous enzymes during the malting process. The resulting carbohydrates will finally be fermented by the yeast. The process is used to produce diet, lite, light, and dry beers.

Mashing

The type of brewing liquid used for beer production plays a very great role. However, with modern technology, any type of liquid with the optimal concentrations of the different ions can be created from any water. Calcium ions contribute to a more acid mash by precipitating as calcium phosphate and thus setting hydrogen ions free from phosphate ions. The pH obtained in this way, 5.4, is favorable for the activities of amylases. Bicarbonate ions act in the opposite way and give a more alkaline mash, which is unfavorable, and thus they should typically be removed. Calcium sulfate is often added to the mash to decrease the pH and to give bitterness to ale. Nitrates and iron ions have deleterious effects on yeasts. For detailed discussions on brewing liquids and salts, see Moll (pp. 133-156).

Germany complies with the Reinheitsgebot, the Purity Law, which, except for Weissbier, permits only barley malt, hops, and water for beer brewing. In most other countries, however, adjuncts up to 50 percent by volume are added to the mash to decrease the cost and to balance the taste of the beer. The adjuncts can be sugar solutions, other malts, or other unmalted cereals, such as rice, maize, wheat, or barley (though both rice and maize must be precooked before their incorporation into the mash, as their starches have high gelatinization points) (Stewart, pp. 121-132).

The mashing can be performed by either infusion or decoction. Infusion mashing is performed in a single vessel at a uniform temperature of about 150°F (65°C), and after the mashing, filtration is performed in the same vessel. The decoction system starts with a low temperature, which is then raised by the removal, boiling, and return of a part of the mash. The whole mash finally is transferred to a separate vessel, the lauter tun, for filtration. In Britain, the infusion is used with well-modified and coarsely ground malt, whereas in continental Europe the larger decoction method is used with a finer grind and less well-modified malt. Decoction mashing is a more versatile procedure for different malts and also has the advantage of low temperature, which helps to maintain the stability of such heat-labile enzymes as proteinases, -glucanases, and -amylase (MacLeod, pp. 59-73; Narziss, 1999; Rehberger and Luther, pp. 247-322).

The objective of the mashing is to produce fermentable sugars from the degradation of solubilized starch, amylose, and amylopectin. The sugars obtained are glucose, maltose, maltotriose, maltotetraose, and higher dextrins to a total of about 70 to 75 percent, with the higher values coming from decoction malting. Unfermentable dextrins persist to the finished beer and are an important part of the mouth-filling experience of the beer. Proteins, peptides, and amino acids, as well as vitamins, inorganic ions, fatty acids, organic acids, tannins, and lipids, are extracted during the mashing and all are important for yeast fermentation.

The amount of malt used is directly proportional to the alcoholic concentration of the finished beer. About one-fourth to one-third of the weight of the malt is metabolized to alcohol.

Wort boiling

The filtered sweet wort from the mashing is transferred to the wort vessel for boiling, which inactivates the enzymes, sterilizes the wort, lowers the pH via precipitation of calcium phosphate and removal of carbon dioxide from bicarbonate, concentrates the wort, denatures and precipitates proteins, dissolves any additional sugars used, isomerizes hop -acids, and removes unwanted flavor components. A long boiling process increases the shelf life of beer. Elimination of high-molecular-weight material (i.e., flocculation of the proteins) is increased by stirring and adding carrageen, a colloid typically extracted from the red alga Chondrus crispus. It has also been shown that the malty full-bodied flavor of beer declines and sharper notes are enhanced with rising temperature of heat treatment. The color of the wort is also increased with higher temperatures, aeration, and higher contents of soluble nitrogen. The process is the same as the one that occurs during kilning, the Maillard reaction (MacLeod, pp. 73-81).

During the wort boiling, hops, whole or powdered, are added to give their characteristic bitterness and aroma to the beer and, because of their antimicrobial action, to increase its shelf life. Principally, there are two types of acids contributed by the hops: -acids such as humulone, cohumulone, and adhumulone; and -acids such as lupulone, colupulone, and adlupulone. The bitter taste of fresh hops derives almost entirely from the -acids, but they have only limited solubility in the wort. However, during the boiling, the -acids are transformed into soluble, bitter iso-α-acids, which contribute to the hoppy bitterness of the beer. There are at least six cis-and transiso-α-acids and their overall level in beer is about 0.0002 to 0.0005 oz/gal (Neve, pp. 33-38). The -acids are largely unchanged during boiling.

The aroma of the hops comes from a very complex mixture of compounds and most of the volatile hop oils are lost in boiling, but a late addition of aroma hops increases the flavor. A discussion and list of the hop compounds in beer is found in Hardwick (“The Properties of Beer,” pp. 573-577).

Fermentation

The principal pathway for carbohydrate metabolism is the Embden-Meyerhof-Parnas pathway, which is the anaerobic metabolism of glucose to pyruvates and alcohol by the yeast cells:

1 mole of glucose gives 2 moles of pyruvates, which will give 2 moles of alcohol and 2 moles of carbon dioxide (CO2).

A more comprehensive equation that describes a brewery fermentation is given by Bamforth (p. 143):

Maltose (100 g) + amino acid (0.5 g) → yeast (5 g) + ethanol (48.8 g) + CO2 (46.6 g) + energy (50 kcal)

Glucose and fructose are the first carbohydrates to be absorbed by the yeast cells from the wort. For the uptake of maltose, the principal sugar of the wort, maltose permease must be synthesized, and before maltotriose can be used, the maltose of the wort has to be almost completely depleted. The formation of maltose permease is the time-limiting effect on the speed of fermentation of the wort. This enzyme is also inhibited by glucose, thus yielding a longer lag period in glucose-supplemented wort (MacLeod, pp. 81-103).

Amino acids can be divided into four groups according to their uptake into the yeast cells: A, B, C, and D in that sequence for both S. c. cervisiae and S. c. carlsbergensis. The A and C amino acids appear to compete with the same permease. Proline, which is the only member of the D group, disappears very slowly, implying that a substantial amount of this amino acid will remain in the final beer: about 0.003 to 0.004 oz/gal.

Unwanted products from the fermentation process, which are closely related to amino-acid metabolism, are certain higher alcohols: 3-methylbutanol, fusel alcohol, and vicinal diketones (diacetyl). Presence of diacetyl seems to depend on a deficiency of the amino acid valine. A deficiency of methionine or an excess of threonine gives unacceptable levels of hydrogen sulfide (MacLeod, p. 91). Consequently, careful control of the amino-acid composition of the wort is essential. Esters (e.g., ethyl acetate) are also important as taste-and aroma-producing compounds. Their formation is favored by high-gravidity brewing followed by dilution, ample supplies of assimilable nitrogen, and relatively high concentrations of alcohol (MacLeod, pp. 81-103). For further discussion on fermentation, see Munroe (1995, pp. 323-353).

The wort is rather rich in B vitamins, but this content, particularly the content of thiamine, is decreased during fermentation by the yeasts (Hardwick, pp. 576-577).

Aging and finishing

Newly fermented beer, often referred to as green beer, has to mature in flavor through storage at low temperatures and should be removed from the yeast. It may also require being clarified, stabilized, carbonated, blended, or standardized. The processes involved include filtrations, CO2 additions, pasteurization, and additions of tannic acid and proteolytic enzymes for clarification of the product. For a more detailed discussion, see Munroe (pp. 355-379). Storage of green beer together with its yeast cells decreases the amount of diacetyl and 2,3-pentanedione, which have a buttery taste that is undesirable in lighter beers. Sulfur-containing compounds, such as hydrogen sulfide, sulfur dioxide, and dimethyl sulfide, may also show up in the beer, producing unattractive flavors and aromas.

During storage, a secondary fermentation can be performed to accelerate aging and the maturation of taste. A secondary fermentation can also be performed in the bottle, as is done in many Belgian ales and Trappist beers, for example. Another method used is to add up to about 20 percent of highly fermenting primary beer (high-kräusen) to the green beer in storage. Also during storage, aroma hops may be added to increase the aroma of the beer, and iso-α-acids from hops can be added to help control bitterness in the beer.

Modern industrial processes of aging and finishing beer, with ultrafiltrations, pasteurization, and total separation of yeast cells, give the modern-style clear, “dead” beer, which has a long shelf life. This contrasts with “real” beer or ale, which retains living yeast cells and thus exhibits richer taste and aroma, but has a shorter shelf life and often greater variation in taste and aroma. Most lagers do not contain yeast cells, but many bottom-fermented beers such as Weissbier mit Hefe (literally, “wheat beer with yeast”), Belgian beers, and British ales and stouts do. A comprehensive summary of the chemical constituents and the physical properties of beer can be found in Hardwick, “The Properties of Beer” (pp. 551-585).

Beer aging and oxidation

Beer is a fresh food product, which undergoes chemical changes during storage. Some of these are expressed as sensory changes shown in the schematic graph given by Bamforth (p. 68). The progression of these changes has been described by Dalgliesch (1977, cited in Fix):

• Stage A is the period of stable, “brewery-fresh” flavor.
• Stage B is a transition period in which a multitude of new flavor sensations can be detected.
• Stage C products exhibit the classic flavor tones of beer staling.
• Stage D, not included in Dalgliesch, “is the development of ‘kaleidoscopic flavors,’“ as exemplified in Rodenbach’s Grand Cru and in Trappist beers, “recalling the subtlety and complexity of great wines” (Fix, pp. 127-128).

Most of these changes are due to a range of oxidative reactions in the beer. Hence, it is extremely important for the quality and shelf life of beer that the beer be oxygen-free. The alcohols in beer can be oxidized to aldehydes and acids, and the iso-α-acids can also be oxidized, with the formation of free fatty acids. All these compounds have prominent effects on aroma and taste. Free fatty acids can also form esters with the alcohols and the unsaturated fatty acids as well as the melanoidins produced via browning of the malt can undergo auto-oxidation. The fatty acids will give fatty and soapy flavor notes. Melanoidins may oxidize alcohols to aldehydes or acids. However, melanoidins can also be reduced by the oxidation of iso-α-acids and work as antioxidants, thereby protecting the beer from oxidation, as is the case in dark beer. The same effects are seen from malt-and hop-based phenols. Together with fatty acids, they interact in a complex electron exchange system.

The different kinds of phenols, from cathecin to polyphenols (also called tannins and flavonoids), which originate from the malt, the hops, and also from the fermentation process itself play a large role in these chemical reactions. They can act as useful antioxidants in the beer and add to the sensory impression of freshness. However, if they themselves become oxidized, they contribute astringency and harshness. Another very important result of the chemical reactions is the reduction of unsaturated fatty acids. This inhibits the development of long-chained unsaturated aldehydes, such as trans-2-nonenal, which is a prominent factor for the development of staling and cardboard and/or papery notes. Because of these reactions, highly hopped beer is less prone to develop the staling effect (Fix, pp. 127-139).

Beer and Social Use

Throughout history, beer-drinking peoples have considered beer an essential part of both their food supply and their enjoyment of life. Bread and beer—food and beverage—were two parts of nutrition united via having almost the same process of fabrication. In earlier times, beer was thought of as liquid bread. As a beverage, it was also preferred over water, partly because water was often contaminated by bacteria, whereas beer became almost sterilized through the boiling of the wort and the antiseptic qualities of hops.

Beer and other alcoholic beverages have played a very important religious and social role: maintaining ties within groups and between people and their deities. It is not surprising that man has considered intoxicated humans to be in close contact with the deities and acquiring spiritual and supernatural forces from them. In Old Norse mythology, mead (an alcoholic beverage fermented from honey) gave humans immortality, wisdom, and poetic abilities. Mead and beer were considered to contain the spirit of the gods, and hence people ingested the gods by drinking the beverages in the same way as Christians drink the blood and eat the flesh of Christ at communion, in the form of bread and wine (Thunaeus, vol. 1, pp. 17-24; Wiegelmann, pp. 533-537).

At the ceremonial feasts of the Nordic people in the tenth century, the beer and food were first blessed and then highly ornamented horns of beer went to everybody to make toasts to the gods: to Odin for victory and power for the king, and then to Njord and Frej for a good harvest and peace. Then they drank minne, memory, for their ancestors and relatives. The ceremony formed and strengthened bonds both between the gods and men, and among men (Thunaeus, vol. 1, pp. 17-24; Wiegelmann, pp. 533-537). In medieval times and persisting until the nineteenth century, important ceremonies such as baptisms, weddings, funerals, and harvest celebrations had öl, beer, in their names; there were, for instance, dopöl, the celebration of baptism, and gravöl, the funeral feast. For the various celebrations, a strong beer was produced. On other days, a much weaker beer was consumed, which was sometimes even mixed with milk. People showed their hospitality by having a tankard with beer standing on the table, and everyone was welcome to take a sip.

These examples from the Nordic countries exemplify the general pattern of mankind using alcoholic beverages as ceremonial links to the gods and a method of creating and increasing social contacts among people. Many of these ceremonies and social implications of drinking together are still active today.

Mixtures of Beer and Other Beverages

In Berliner Weisse, juices of red raspberry, green sweet woodruff, or, more recently, pineapple may be added. To Belgian Lambic, different fruits can be added to the second fermentation to create, for example, Kriek (using cherries) and Framboise (using raspberries) ( Jackson, 1991, pp. 95-100).

The English shandy (beer mixed with lemonade or ginger beer) and the German Radler and Alsterwasser (beer mixed with a clear soft drink, typically lemon or lemon-lime soda) are quite popular today. Shandy has a tradition that dates back to the tenth century (Zotter, pp. 222-223). Alsterwasser has also become popular with cola and tequila (Pini, pp. 88 and 788). Radler was earlier a common mixture for children and young people in Germany. In southern Sweden, the mixture of beer (svagdricka) and milk called drickablandning (mixture of drinks) was very popular until about the middle of the twentieth century.

Food and Beer

Beer is used as an ingredient in food preparation in soups and stews, for marination of meat, as a liquid for boiling, and in sauces. Many German examples are given by Lohberg (pp. 269-331). Traditional soups with beer in northern Europe are Biersuppe, Öllebröd, and Ölsupa, which are boiled mixtures of beer and meal and/or milk and egg, with ginger, cinnamon, and fruits. Carbonade, beef stewed in beer, is a favorite dish in northern France, Belgium, and the Netherlands.

The specific types of beer used traditionally in an area almost always fit very well with traditional local food. The most popular type of beer in the world today, pilsner or light lager, which is served cold and has low levels of bitterness and maltiness, is a good partner with almost any kind of food, which may well be an important reason for its popularity.

Other types of beers, which have a more complex taste, should be paired with different foods using some care, as the combination should not overpower the individual flavors of either the beer or the food, but enhance the positive features of both. A nice introduction with illustrative food and beer combinations has been presented by Jackson (1998). In general, beer can be paired with different kinds of food as well as wine can be, and sometimes better.

Service Traditions

Drinking vessels and beer containers

In Latin America, the Incas and the Mayas developed very elaborate containers both for the production of chica and for storage and ritual drinking. The malting and fermentation took place in hollow tree trunks that were often decorated and covered with carpets or palm leaves. The bottles were ceramic stirrup vessels with a long neck, sometimes two joined into one, with a round bellow that could be formed as a human head. Ordinary ceramic cups were also used. The ceramics were painted with many different scenes, often with a strong erotic touch. Bottles filled with chicha were buried with the dead (Rätsch, p. 103).

The serving of beer in Mesopotamia and in ancient Egypt was from ceramic containers, both large ones from which people drank with straws (primarily to penetrate the top-fermenting yeast and floating husks) and smaller ones like our cups. For ceremonial drinking, elaborate bull’s horns were used in northern Europe. After the ceramic period and persisting into the twentieth century, the wooden barrel and the wooden tankard were the principal storage and drinking containers. In Scandinavia, it was common to have elaborate drinking bowls, often in the form of a goose, for ceremonial feasts, and during the sixteenth century, the upper class used ornamental wooden drinking vessels (Hirsjärvi, pp. 57-68; Cleve, pp. 15-42; Gjærder). Drinking vessels were also later made of lead, tin, copper, silver, stoneware, ivory, china, or glass. Tankards usually had the same general design whether or not they were lidded. Lids were usually metallic, and the rest of the tankard was made of glass, ceramic, or wood. There were very elaborate, expensive tankards and also simple and practical ones ( Jung; Lohberg).

Although its history is very long, perhaps as long as the history of beer itself, before the nineteenth century the beer glass was seen only among the upper classes. It was the technique of glass pressing in great industrial scale in the nineteenth century that made the glass available to everyone. The design of the beer glass has developed in some distinctive ways, with special sizes and shapes for specific types of beers and special glasses displaying the names and logos of the brewers for almost every brand of beer (Lohberg; Jackson, 1998). Jackson includes color images of both the glass and the bottle for each type of beer presented in the book.

The original wooden barrel was generally replaced in the twentieth century by the steel barrel. At the end of the nineteenth century, glass bottles were introduced, and beginning in 1935, they were joined by metallic containers—beer cans.

Serving temperature

There is a correct serving temperature for every beer. The richer the flavor and aroma of a beer is, the higher its serving temperature should be. A very low temperature is suitable if taste is secondary. The only beers that are appropriate to serve cold, about 39°F (4°C), are light, pale lagers. More tasty lagers should be served between 43 and 50°F (6 and 10°C), and ales between 54 and 64°F (12 and 18°C). Jackson (1998) is a good source for recommendations of serving temperatures for specific beers.

Beer and Traditional Medicine

Hans Zotter’s book (pp. 222-223) contains medical recommendations and rules from Ibn Butlan from the tenth century. It illustrates how beer was looked upon medically in the old tradition of Hippocratic medicine, a tradition that prevailed until about the seventeenth century. Its view was that

• Beer is “hot and humid”; or “cold and humid.”
• The best beer is sharp and spicy.
• Beer drinking relieves the sharpness of heat and drunkenness.
• It dilates the vessels and creates discomfort.
• In contrast, the mixture of beer and lemon juice or citric acid helps.
• Beer drinking creates “malicious body fluids,” which are good for people with hot “complection” and for young people, especially during hot weather and in hot countries.

In 1614, the philosopher and alchemist Paracelsus wrote: “Cerevisia malorum divina medicina” (Beer is a divine medicine against harms) (Rätsch, pp. 12-14). Beer was also used as a carrier or solvent for many different folk remedies (Rätsch, pp. 28-40). The use of herbs and spices, such as hops and sweet gale, in beer may well have its origin in folk medicine.

Interestingly, beer is still prescribed today in the United Kingdom as a medication for the elderly.