Only four ingredients are necessary to make beer: water, malt, hops, and yeast. Despite its ancient origins and long history, and this seemingly short list of ingredients, the manufacture of a quality beer remains a rather challenging task. In part, this is because beer making consists of several different and distinct processes that are not always easy to control. In addition, some steps taken to improve one aspect of the process—for example, filtering the finished beer to enhance clarity—may at the same time remove desirable flavor and body constituents.
The actual brewing process involves not only the well-studied yeast fermentation, but also entails other biological, as well as chemical and physical reactions. It is, therefore, convenient to consider the beer manufacturing process as consisting of several distinct phases or steps.
The primary purpose of the first phase, called mashing, is to transform non-fermentable starch into sugars that the yeast can ferment.The process, which is enzymatic in nature, involves a series of biochemical events that starts with the conversion of cereal grain, usually barley, into malt.The malt is then used to make a mash, ultimately resulting in the formation of a nutrient-rich growth medium, called wort. Although other grains, such as sorghum, maize, and wheat can also be malted, barley is by far the most frequently malted cereal grain.
In the second, or fermentation, phase, which is microbiological in nature, sugars, amino acids, and other nutrients present in the wort are used to support growth of yeasts. Yeast growth, under the anaerobic conditions that are soon established, is accompanied by fermentation of sugars and formation of the end products ethanol and CO2. Technically speaking, the fermentation step results in beer that could then be consumed. However, at this point, the beer contains yeast cells, insoluble protein-complexes, and other materials that cause a cloudy or hazy appearance.In addition, carbon dioxide is lost during the fermentation. Beer at this stage is also microbiologically unstable and susceptible to spoilage. Therefore, additional measures are almost always taken to remove yeasts and other microorganisms and any other substances that would otherwise affect product quality and shelf-life and to provide carbonation in the final product.
In this chapter, therefore, a third phase, consisting of important post-fermentation activities, also will be discussed.These latter steps of the beer-making process, some might argue, are among the most important, since they have a profound effect on the appearance, flavor, and stability of the finished product.The general beer manufacturing process is outlined in Figure 9-3. As the reader will soon be aware, many beer-specific terms, such as mashing, are used to describe the brewing process. Some of these terms are defined in Box 9-2.
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Discover How To Become Your Own Brew Master, With Brew Your Own Beer. It takes more than a recipe to make a great beer. Just using the right ingredients doesn't mean your beer will taste like it was meant to. Most of the time it’s the way a beer is made and served that makes it either an exceptional beer or one that gets dumped into the nearest flower pot.