Beer is an alcoholic beverage most often brewed from malt barley, water, hops, and yeast. It varies in taste, color, and alcohol content depending on the process used to brew, age, and store it.

History

Sumerians may have discovered fermentation about 6,000 years ago; records prove they brewed beer at least 4000 years ago. Beer has been an important part of nearly every culture since then.

Babylonians brewed at least 20 types of beer, exported and distributed as far away as Egypt. In the middle ages, beer was often safer to drink than the local water, which could be contaminated.

Ingredients

Many things have been used to flavor beer including juniper berries, blackthorn, bay leaves, thorn apple, rosemary, oak bark, wormwood, caraway seed, and Saint-John's-wort but the most common used after the 9th century is hops, which produces a milder beer. Beer is also less perishable and the brewing process more stable because of hops.

Malt extract, made from malted barley or wheat, is used as the basis for many beers. It provides the sugars that the yeast will consume. Different colored malt extract makes different varieties of beer. Besides the extract, most beers also have some form of malted grain, and sometimes unmalted grains such as oats or wheat.

Some grains, like rice or corn, which are referred to as adjuncts, or a sugar such as table or corn sugar, can be used in place of malts to make a thinner beer with less flavor.

Hops [pictured at right], which is a flower, is used to flavor beer. Different flavors can be obtained depending on when the hops are added during the brewing process. Different varieties of hops contribute to different varieties of beer.

Yeast converts sugars from the above ingredients into alcohol and carbon dioxide. Ale yeasts make produce fruity flavors while lager yeasts are neutral in flavor.

Water is the largest ingredient in beer. The minerals in the water and the pH balance can effect the taste of the brew. Tap water can be used, but chlorine can cause a harsh flavor.