BEER INGREDIENTS - WHAT ARE THE INGREDIENTS OF BEER?

Beer is a fermented beverage made from a source of starch without concentrating the alcohol. The composition of finished beer varies, but the approximate averages for the major components of American commercial beers are about as follows: beer composition

Water 92.9%
Ethanol 3.9%
Carbohydrates 2.5%
Carbon dioxide 0.5%
Protein 0.2%

This simple analytical result masks a complex reality. Hundreds of minor components not listed above are big players in the flavor and character of the beer. Instead of taking on the issue of what is in finished beer, we will look at how beer becomes beer.

The usual ingredients for beer are water, malt, hops, yeast, and adjuncts. Adjuncts are materials that supplement the malt by providing additional starch or sugar.

Malt
Malt is seeds of grain that are allowed to sprout and are then killed by heating. Most beer malt is made from barley (Hordeum vulgare) seeds. Wheat is used for certain styles; oats, rye, sorghum, millet, and others are occasionally used for specialty or regional styles. Malt serves as a source of starch and also provides enzymes to break down the starch into sugars that can be fermented.

Barley, among the first plants domesticated as a crop, seems to have originated in what is now the Israel–Jordan area. As a consequence of its importance to civilization, some ancient religions used barley in their rituals.

Barley is mentioned many times in religious texts including the Bible. Each barley plant has one or more stems that, for modern varieties, extend 2 to 3 feet (60 to 90 centimeters). The stem is divided by joints called nodes, each of which has a leaf. The flowering head grows from the top node.

There are groups of three closely spaced flowers at points along one side of the stem of the flowering head. The next group of three flowers is on the other side of the stem. This gives six rows of flowers.

In some varieties of barley, all the flowers are fertile, so after fertilization there are six rows of seeds, called corn. These varieties are called six-row barley. In other varieties of barley, only the central flower of each group of three is fertile, so there are two rows of corn.

These varieties are called two-row barley. The barley corn has a groove in the front (ventral) side where it grew against the stem. The corn is covered with interlocking woody shells called hulls, one in front and one in the back; the back hull extends to form a characteristic awn, also called a beard.

Beneath the hulls is a waxy seed coat. Beneath the seed coat is a layer of living cells called the aleurone layer. There is a hole in the seed coat, called the micropyle, where the hulls meet at the end of the corn away from the awn. The micropyle can admit water. The baby plant, called the embryo, is at this end of the corn.

The compartment containing the embryo is separated from a compartment containing starch, called the endosperm, by a divider called the scutellum. The endosperm contains granules of starch, each surrounded by a protein coat.

Whether the beer is to be made from barley or some other grain, the seeds are first converted to malt, a process called modification. The live seeds are soaked in water (“steeped”) on and off for about two days. They are then put into a box or spread on a floor, provided with moist air, and turned regularly.

During this period the embryo wakes up and releases chemical messengers called hormones. The hormones direct the cells in the aleurone layer to produce enzymes. The enzymes break down the proteins and starch in the endosperm so that the embryo can use them for nourishment until it is able to produce its own food from sunlight.

Before this process goes too far, the maltster puts an end to it by heating the germinating seeds in a huge oven called a kiln. The temperature is held at 175 to 212 °F (80 to 100 °C). Longer kilning at higher temperatures gives darker, more flavorful grades of malt, but these treatments also destroy a larger fraction of the enzymes.

Hops
The hop is a climbing plant, Humulus lupulus. Hop flowers, which look like little pine cones, are used to flavor beer. There are many varieties of hops with names like “Cascade” and “Spalt.” All give bitterness, but the different varieties of hops give different flavors.

Hops are like wine grapes in the sense that the details of the growing temperature, soil, moisture, and other climate issues affect their flavor. Wine makers deal with variations in grapes by marketing wine as “vintages.”

Consistency in wine is not expected from one year to the next. Brewers do not have this luxury. Some use mixtures of hop varieties so that the proportions can be modified to adjust for local and seasonal variations.

Small craft brewers cannot usually keep a big hop inventory on hand, so their product is not as consistent. In the Northern Hemisphere hops are harvested in the late fall and must be dried and cold-stored until used to make beer.

Yeast
Yeast is a single-cell fungus that reproduces by budding. Hundreds of species of yeast have been characterized. Of these, two are usually used for beer making. Saccharomyces cerevisiae, known as top fermenting yeast, is used in ale, and Saccharomyces pastorianus, a bottom fermenting variety, is used in lager. There are some other species of the genus Brettanomyces that are used in a Belgian ale style called lambic.

Water
You know about water. It turns out that traces of various minerals naturally present in water affect beer in important ways. The chemistry of water is the chemistry of life.