Sometimes a problem is cleverly turned into an advantage.
The world is indeed fortunate that barley is good for little more than making beer. But for that, it is excellently suited.
Barley malt, beer's basic ingredient
Barley is a cereal grain, similar to wheat or oats, that doesn't mill well into flour for bread. But crushed and dried in a process called malting, it forms the perfect base for making the prime ingredient in 'wort', the liquid that is fermented into beer.
It grows in a variety of types, distinguished by the number of seeds on the stalk of the plant. Two, four or six seeds form the majority of barley plants, with European brewers traditionally preferring the two-row type and Americans more often the six-row.
Two-row barley malts well, and has a higher starch to husk ratio than the four or six-row variety. That leads to rich, malty brews of the type preferred by the English. U.S. brewers often prefer the six-row for economic reasons, but also for its higher concentration of enzymes. Those enzymes aid in converting the starch into fermentable sugars (primarily maltose).
The malting process starts by soaking the grain, causing it to begin to germinate. Small rootlets sprout and the grain is then kiln-dried, crushed and roasted.
How that roasting step is carried out plays a large part in determining the color and flavor of the final product. Roasting stops the germination process, but - if stopped in time - leaves needed enzymes active.
One enzyme - diastase - is chiefly responsible for converting barley starch into maltose, the sugar that yeast converts to alcohol and carbon dioxide during fermentation. Carried out further, roasting can destroy those enzymes but adds flavors to the final product. Both actions are typically part of the process.
The roasted grain then goes through a process called 'mashing', in which the starches are converted to sugars and dissolved in hot water (to make 'wort'), in the first phase of brewing. Most home brew kits containing malt are actually dried wort.
Malt preparation is a science in itself and brew chemists are continually striving to improve the process. Given the over 800 compounds in beer - many of which are contributed by the malt - that's not an easy task.
Malting has a significant effect on the flavor, naturally. But even good malting processes can inadvertently add unpleasant characteristics to the starting material of beer. Malt components can cause bottom-fermenting yeast (used in lagers) to flocculate (gather) prematurely. They can produce off-flavors, alter the foaming character, produce haze and even introduce toxins into beer.
Flavor is influenced not only by the maltose, but also by the organic acids produced from germinating. Those help balance the sweetness of the sugar with sour aspects. The bitter aspect come primarily from hops added during brewing.
One of the most remarkable features of malt is how uniform brewers are able to make it, given its natural variation. Like any agricultural product, barley has components that vary in relative concentration with every farm, year and plant.
Keeping one brand or type of beer the same from bottle to bottle depends to a large extent on keeping the malt uniform from batch to batch. Weather, soil management, grain size, soaking and drying time, crushing styles and much more contribute to the final result. The techniques used to accomplish uniformity would fill several volumes.
So, next time you're brewing up a batch at home or just downing a glass at a local pub, think a moment about the starting ingredient and the effort needed to produce and use it. As with grapes and wine, without malt there would be no beer. On second thought, don't think about that.