CHAPTER 1
Barley
Barley has been the brewer’s preferred source of fermentable extract since prehistory. The barley kernel is readily malted, contains adequate enzymes to convert its starch to sugars, and upon mashing, yields a very complete, highly soluble extract that is relatively free of unwieldy constituents. Barley gives beer its characteristic sweet-to-malty taste, as well as its body, head, and color. Other grains such as wheat, oats, and rye do not lend themselves so readily to brewing.
The barley kernel is the seed of a plant of the grass family (Gramineae). It is one of the hardiest of all the cereal grains and is able to grow under widely varying conditions from Alaska to the equator; it grows best, however, in cool, dry climates.
The seeds grow in two, four, or six rows, called heads, along a central stem. The number of seed rows is determined by the number of fertile flowers; in two-row types only two of the six flower clusters are fertile, whereas all the flowers of six-row barley are fertile. Long, thin bristles protrude from each seed, producing a “bearded” grain that closely resembles wheat.
Harvested when fully ripe, malting barley is dried from a moisture content of 15 to 25 percent down to below 14 percent and is binned for six to eight weeks before being malted. It is then graded; only the largest (greater than three-thirty-seconds of an inch in width) of the four standard grades is considered suitable for malting.
One bushel of brewing-grade barley weighs forty-eight pounds, and it should be at least 95 percent germinant. The kernels should be of uniform size, glossy, uniformly straw colored (light to dark yellow), plump, and have a clean grain aroma. There should be no rancid, moldy, or musty smell, nor any slender, immature grains with greenish-white husks. The husks should be thin, finely wrinkled, and tightly jacket the kernels. The endosperm (starch) must be opaque, white, and mealy, not translucent, grayish, steely, or glassy. Steely grains are excessively high in nitrogen, contain a greater percentage of poorly soluble protein, and do not take up moisture as readily. Consequently, nitrogen content should not exceed 1.6 percent where the barley will not be well modified or where the malt will be infusion mashed. Except where the wort will contain a high percentage of adjuncts, the nitrogen content should never exceed 2 percent. The protein-to-carbohydrate ratio should suit the type of beer being brewed and the processes used to brew it.
European brewers prefer superior two-row, thin-husked, large-berried barley varieties, which give the best brew-house yield, clarity, and flavor. These have a more favorable starch-to-protein/husk ratio than other barleys and yield a mellow flavor and good clarity.
Six-row barley is the most economical to grow because the greater number of rows per head increases the per-acre yield. It is a warm-climate barley and is the type most widely grown in the United States. It is favored by domestic commercial breweries because it is rich in the enzymes needed to convert the adjuncts they employ (adjuncts may account for up to 60 percent of the extract in U.S. brews). Because six-row barley is high in protein, in all-malt brews it presents problems with clarity and stability. Its higher husk content improves mash filterability but can contribute harsh flavors, especially when brew-house practices cause hot-side aeration.
Barley Corn
Four-row barley is still grown and malted in Northern Europe, where it has long been prized for its hardiness in the cold climate. It is not widely used elsewhere, however, because of its steeliness and low yield. It is actually a six-row barley that appears to form four rows, rather than six, because of its thin, elongated head.
Modern barley varieties have been selected for improved field and maltings yields. Improved varieties have replaced older cultivars several times during the past twenty years, and will continue to do so. Thus far, the only appreciable improvement in brewing quality that has been realized is the lower nitrogen of six-row varieties, and in many cases “improved” varieties have been rejected by brewers.