The hops are the female flower of the hop plant. They are a member of the cannabaceae family, which also includes hemp. The malt provides sweetness to the beer and the hops balance with bitterness. Hops weren’t always used in beer but the balance of the malts was still needed. Great was a blend of herbs and spices used to induce bitterness. Hops became a staple in beer due to their battering qualities as we as flavor, aroma and mild antimicrobial properties.
The bitterness comes from the alpha-acids. Hops must be boiled to convert the alpha-acids into a soluble form (isomerization). The longer they are boiled the more bitterness is extracted from the hops. This comes with a tare-off: the delicate aromatics of the hops are driven away in the boil. Hops are normally added at different times during the boil to get the best of both worlds.
There are many different breeds of hops each providing a different taste, aroma and potential bitterness to the beer.
Yeast is the single-celled fungus that is responsible for creating the alcohol and carbon dioxide from simple sugars. They also have impacts on the flavor that can vary widely.
There are two species of brewers’ yeast: ale and lager. Ale yeast is a top fermenting yeast, which means it generally rises near the surface of the beer during fermentation. It is usually fermented at temperatures around 68F. Lager yeast is bottom fermenting. They can tolerate colder temperatures and are usually fermented around 55F. Because it is colder, they work more slowly meaning more time is needed to complete a fermentation and less activity to carry them to the top.
Among ale and lager yeast there are dozens of different strains. Each strain has its own characteristics and flavor profile. This is why a Belgian ale is distinctly different from an American ale despite both beers being ales.
Malt is a term that can be applied to various grains, but the most common used in brewing is barley. The barley plant looks a lot like wheat, but the grain is contained in a husk. Before barley can be used to make beer it must be malted.
Grains are a type of seed that contain carbohydrates, in this case starches. Malting provides a way for brewers to harness these starches to make beer. The barley must be allowed to germinate, or to sprout. This is done by soaking the barley in water for several days, draining it and holding it for several more days. The water enters the husk and starts the germination of the barley - at this point it is called green malt. Barley contains locked-up energy in the form of starches that can sustain the growing seed until it can produce its own energy using photosynthesis. The germination process releases enzymes for the barley to convert these starches into sugars that can give it energy to grow. The key to the malting process is to stop the germination of the barley at a point after the sugar-converting enzymes are released, but most of the starch is still unconverted. Eventually, these enzymes will produce the sugars that will feed the yeast to make the alcohol in the beer.
After this process has released the enzymes, the green malt is kilned (dried) by gradually raising the temperature. The flavor and color of the malt depends on how high and how long the temperature is raised and sustained during the kilning process. Most breweries buy barley that has already been malted. To their specifications. Other malted grains include wheat, rye and oats. Sometimes there are cases here unsalted grain is used, but it usually compromises only a small portion of the total recipe.
Water is often overlooked, but necessary to brewing beer. Beer is mostly water, after all! The mineral in the water play important roles throughout the brewing process and final flavor of the beer. There can be negative impacts as well (chlorine as an example) making it important to monitor water quality for brewing. Many breweries use reverse osmosis (RO) systems to strip the water of almost all dissolved minerals, solids and compounds then add back the necessary minerals for flavor and the brewing process. However, a rule of thumb, is use water that tastes good.