At its most basic form, beer is made of four ingredients: water, grain, hops and yeast. Yet, despite its simple ingredient list, beer brewing can be a touchy process, where the slightest variation in temperature, timing, or type of ingredient can offset the balance of flavor, which is why so many different types of beer exist.
If you remember, in ancient times beer was safer to drink than water because water sources contained so many contaminants. Today, breweries take special precautions to filter water of any chemicals, even ones like chlorine that do no harm, in order to maintain flavor and consistency of brand. Even home brewers are encouraged to use purified water to achieve the best quality of beer, since beer is ninety to ninety-five percent water.
Grain is the ingredient that produces sugars in order for the yeast to ferment. If you begin to research ingredients for beer, say, for home brewing, you may see grain referred to simply as barley, but people often use other grains like corn, rice to supplement their beer.
Grains must be malted in order create the sugars that encourage fermentation. The malting process begins by soaking the grains until they begin to sprout, then draining them and monitoring their growth until the sprouts are producing sugar but the starches haven't yet begun to convert. The sprouts, at this point called green malt, are then dried by gradually raising the temperature of their environment. This step has great impact on the overall flavor and color of the beer. Since this is such a delicate process, most breweries outsource the malting of their grains.
American Homebrewers Association director Gary Glass explains how grains are malted for brewing
As you already know, hops were introduced to beer relatively late in the game, in the sixteenth century by the Bavarians. Hops act as a natural preservative, giving beer a longer shelf life, in addition to providing the bitterness that balances the natural sweetness of the malted grains. In America, most hops are grown in Washington State, although increasingly, people are beginning to grow hops on a small scale elsewhere.
After the sugars are extracted from the malted barley, they're added to a brew kettle with the hops and boiled for an hour and a half. The lengthy boiling time allows the bitterness of the hops to emerge, but it's the hops added at the end of the boiling time that contribute to the overall flavor and scent of the final product. The mixture of malted barley and hops is called the wort.
Yeast activates the fermentation of beer, and it's what creates the alcohol and carbonation in beer. Ale is made using top-fermenting yeast, which involves a shorter fermentation period of two weeks at warmer temperatures (68 degrees). Lager, on the other hand, is made using bottom-fermenting yeast. The fermentation for lager is six weeks at cooler temperatures (forty-eight degrees).
Once the solids are extracted from the wort, the mixture is cooled to the appropriate temperature for yeast. As fermentation reaches its end, the yeast is removed and may be used again for future batches of beer. During most of the fermentation process, a tube allows the CO2 to escape, but after the yeast is removed the container is sealed off, creating the carbonation that beer is known for.
While beer only has four main ingredients, they aren't the only ones used in brewing. What differentiates one beer from another may be the proportion of these four ingredients, or the methodology of brewing, but additional flavoring may be added in the form of spices, fruit, or other flavors (like chocolate and coffee). These additional ingredients are called adjuncts.
Adjuncts may also include the use of rice and corn, which many large breweries use as filler to make less expensive beers. In Germany, under the German Purity Law, the use of any adjuncts in lagers is prohibited.
There are several ways to add adjuncts for flavor or aroma:
Now that you know about the process of brewing beer, you may be chomping at the bit to get your own brew on. In the next chapter, we'll talk about what you need to start your own home brewery.