If you are already familiar with the brewing process, you may want to skip this section and go on to the next chapter. My intent here is to give a very brief, basic outline of brewing — sufficient, I hope, to make the remainder of the book intelligible to those who have never made a batch of beer.
Beer is a fermented beverage. What does that mean? Basically, fermentation is the metabolic process by which yeast takes sugar and splits it into alcohol and carbon dioxide. This, of course, is what beer makers and drinkers are interested in. You might call me a yeast farmer. My job is to produce sugar solution and feed it to my yeast.
There are lots of ways to create a sugar solution, but if we want to make beer — as opposed to wine or sake or mead or some other beverage — then the main source of our sugar must be malted grain, specifically malted barley, which is usually just called malt. The making of malt is a difficult task in its own right: the raw barley must be soaked, sprouted, and then dried in a kiln (a hot-air oven). Each of these steps is exacting, and changes to time, temperature, and other variables can make a large difference in the outcome. Likewise, the breed (or strain) of barley and its exact constituents play a role. This is not the place for a detailed listing of the basic types of malt and their characteristics, but if you have never brewed before, you need to understand that malt is not all alike: different malts have vastly different colors, flavors, and other properties. In the modern world, malting usually is a separate industry that supplies standardized products to the breweries, which are their customers. Only a few breweries still maintain their own malting departments.
The reason brewers need malt, rather than some other type of grain, is quite simple. Malt contains enzymes that can break down starch into sugar. In fact, the difference between beer and other fermented drinks comes down to this: the main sugar source is malted grain whose starch has been broken down into fermentable sugars by the action of its own enzymes.
So, how do we accomplish this breakdown? We make a mash. That is, we crush (mill) the barley malt, then mix it with water in a kettle or other vessel, and heat it to around 150°F, a temperature at which the starch will be quickly and efficiently reduced to maltose and other sugars. Ordinarily, a stand of one hour at conversion temperature is more than enough to complete the process.
The next step is to separate, or strain, the newly created sugar solution — which is now called wort — from the husks and other remaining grain solids. In a good mash, about 80 percent of the grain (by weight) will convert to sugar and other soluble matter, but the other 20 percent needs to be removed, for the sake of both flavor and aesthetics (clarity). This is done in a vessel called a lauter tun, and the process is known as lautering. The lauter tun is fitted with a straining device — usually a slotted false bottom. Once the mash has been moved to the lauter tun, a valve beneath the false bottom is opened and the wort is drawn off and returned to the surface of the grain bed. As this re-circulation continues, a filter bed forms and the wort will gradually clarify. When the wort is judged sufficiently clear, recirculation ends and the wort is run into a kettle. However, much of the wort will remain trapped in the spent grain solids, so after drawing off as much liquid as possible, the grain bed is usually rinsed, or sparged, with hot water. Sparging greatly increases efficiency and, for a normal-strength beer, can allow recovery of 90 percent or more of the sugar formed during mashing.
After the full volume of wort has been collected in the brew kettle, it is brought to a boil and boiled for one to two hours. During this time hopsare added. The hop is a bitter herb, and one of the main purposes of boiling is to dissolve the hop resins and impart their characteristic flavor to the wort (and beer). Other purposes of boiling are to concentrate the wort, to deepen its color slightly, and most important, to sterilize it. We want to make sure that our carefully selected brewer’s yeast has no competition from bacteria or other organisms. Along with careful cleaning and sanitizing practices, the boil is the brewer’s primary weapon in the battle for clean-tasting beer.
After the boil is over, the hops and trub (coagulated protein) are separated from the hot wort. Depending on the form of the hops, one of two methods is used. Hop pellets break up into fine powder in the kettle and can be removed by whirlpooling; however, if whole leaf hops have been employed, they must be strained out in a vessel called a hop back or hop jack, which often resembles a shallow lauter tun. In any case, after kettle solids have been removed, the wort is sent to a cooling device, where it is dropped to room temperature (or lower) and then moved on to the fermenting tank, where yeast is pitched and the transformation from wort to beer will take place.
In the fermenter, yeast is added (the brewer’s term is pitched) and the yeast begins to multiply and also to ferment. Fermentation can take anywhere from three to ten days, depending on temperature and other factors. Over the first one to three days, it builds to a peak, and then gradually tapers off. When the yeast has turned all the wort sugar into alcohol and carbon dioxide, the beer may need a period of aging to allow the spent yeast to complete its work by reducing some of its intermediate by-products (this is called maturation), and also to settle out. At the end of this step the beer is basically ready. It may require carbonation and/or clarification before it can be put in a package (for example, a keg) and served, but once the maturation is done and the yeast is removed, the flavor has reached its peak. Beer is not like wine: it does not improve in the bottle, and it is best drunk young. The only exceptions are very strong beers that still contain some live yeast. Storage conditions greatly influence the rate of deterioration. Besides time, the enemies of beer are heat, motion, and oxygen. The more air in the package, the shorter the shelf life will be.
TO SUMMARIZE, THE STEPS IN MAKING BEER ARE:
- 1. Milling the malt
- 2. Mashing
- 3. Lautering and sparging
- 4. Boiling the wort
- 5. Cooling
- 6. Yeast pitching and fermentation
- 7. Maturation and clarification
- 8. Packaging
Packaging is the final step before consumption. It is easier to keep air levels low in a larger container, which is one reason kegs are usually preferable; however, the main reason is that it is much easier to clean and sanitize a single 5-gallon keg (for example) than to do the same to 50 bottles. The only drawback is difficulty of handling.
Each of these steps requires dedicated equipment. In the next chapter we will look at how the brewing process is implemented in a brewpub, where space and capital must be kept to a minimum, without sacrificing quality.