Let us talk for a moment about how beer is made. It isn't necessary to have a degree in brewing in order to enjoy beer but, an understanding of the basic steps of how beer is made can enhance your enjoyment of the various styles and varieties of beer available on the market today. If you ever plan to visit tour some breweries or maybe even get into brewing your own beer, it can be instructive to have an idea of what goes into making beer.
Beer starts in the barley field. Here we find two basic different types of barley, two row and six row. This distinction refers to the rows of kernels at the tip of a stalk on the barley plant. Each contributes differently to the brewing process but, as a drinker its really not important to understand how. It is enough to just be aware that the two varieties exist.
After harvesting, raw barley is malted to get it ready for brewing. Malting is a process whereby the grains are soaked in water and encouraged to sprout. Then, just as the tender shoots emerge from the kernels, the grain is dried and rapidly heated. This produces just the right mix of starches, enzymes and proteins for beer. After drying, the kernels of malted barley are cracked to expose all that goodness inside. Now they are ready for brewing.
Once in the brew house, the malt is soaked in hot, but not boiling, water. This very warm bath excites the enzymes which start eating the starches in the grain producing sugar. During the process, brewers can gradually adjust the temperature up for different results that ultimately translate into the final beer's complexity, flavor and alcoholic content. Eventually, the temperature of the water is increased to the point that the enzymes shut down and the sweet water, now called wort, is drained away from the grain.
The wort is collected in a brew pot where it is heated to boiling. Most beer is boiled for around an hour although that varies according to style and the brewer. During the boil hops are added. Hops added early in during the boil contribute a bitter underpinning to the final beer. When hops are added later in the boil, the final beer retains some of the more delicate features of the flower like aroma and flavor. Most beer styles use some combination of both bittering hops and aroma hops.
When the wort has boiled long enough it is rapidly cooled and, depending on the brewer, filtered. Then it is transferred to fermentation tanks where yeast is added and the magic begins. In the dark, air-tight tanks, the yeast sets to work eating the sugars. The by-product is alcohol and carbon dioxide. The alcohol, of course, is essential to the final product. The CO2, well, most of the CO2, is expelled from the tank via an air-lock which allows the gas to escape but lets no potentially contaminating air back in. Under the right conditions, yeast can convert wort to beer in just a week or two.
I have heard it said that yeast is the most important ingredient in beer. I cannot agree with this, without any of the base four ingredients - cereal grain, water, yeast and hops - beer does not exit so they are all equally important. However, I can agree that yeast is the most important ingredient in determining beer style. There are two basic classes of brewers' yeast, lager and ale. Within each class, there are dozens of different strains of yeast that determine the style. Different strains will produce different flavors in the final beer. Many of the English style ales count on yeast strains that produce rich, fruity, complex and sometimes even muddy flavors in the beer which fermenting. German lager yeasts, on the other hand, produce very few additional flavors and ferment very cleanly and efficiently, extracting more alcohol from the sugar in the wort than their English cousins.
Continued at How beer is made - Lagering and Packaging