What is beer exactly? By excruciatingly simple definition, beer is any fermented beverage made with a cereal grain. Specifically, beer is made from these four primary ingredients:
Grain (mostly malted barley but also other grains)
Hops (grown in many different varieties)
Yeast (responsible for fermentation; based on style-specific strains)
Water (accounts for up to 95 percent of beer’s content)
Grain provides five things to beer:
Color: The color of the grains used to make a beer directly affects the color of the beer itself.
Flavor: The flavor of the beer is primarily that of malted barley, although hops and yeast characteristics play a secondary role.
Maltose: Maltose is the term for the fermentable sugars derived from malted grain. Yeast converts these sugars into alcohol and carbon dioxide.
Proteins: Proteins in the grain help form and hold the head (foam) on the beer.
Dextrins: Dextrins are the grain components that help create mouthfeel (the feeling of fullness or viscosity) in the beer.
Hops provide beer with four attributes:
Bitterness: Bitterness is essential to the flavor balance of the beer; it offsets the sweetness of the malt.
Flavor: Hops have flavor that’s distinctly different from bitterness, and it adds to the overall complexity of the beer.
Aroma: The piquant aroma of hops, which mirrors their flavor, is derived from essential oils in the hops.
Stability: Hops help provide the beer with stability and shelf life; their beta acids stave off bacterial contamination.
Brewers choose yeast strains based on which style of beer is being made. The two main classifications of beer yeast are
Ale yeast (Saccharomyces cerevisiae): Top-fermenting
Lager yeast (Saccharomyces uvarum): Bottom-fermenting
The quality of brewing water is extremely important because beer is about 90 to 95 percent water. The mineral content of water can be manipulated and adjusted according to the requirements of the beer style being brewed.