Brewing beer is a process that has roots dating back to 12,000 years. It is a mix of science and art.
The process begins with raw barley, wheat, oats or rye that has germinated in a malt house. It then goes through a mash tun, where the grain is heated to certain temperatures to release enzymes that break down starches into sugars.
Malt
Malt is a special type of grain that has been specially prepared to be used in brewing. It’s the primary sugar source for beermaking, as well as a key ingredient in many other beverages such as cider and mead.
Barley is the most common type of malt, but other grains are also used. Most brewers use a combination of base malt and specialty malts to get different flavors in their beer.
In the brewing process, base malts are soaked in water at a certain temperature for a specific amount of time, which extracts the fermentable sugars from the grains so yeast can ferment them into alcohol and create beer. The resulting liquid is then dehydrated into either a thick syrup or dry-powdered form.
Specialty malts are dried in a kiln at higher temperatures for longer periods of time, roasted, or both to develop the flavor and color characteristics of each specialty malt. The drying process also varies the moisture level of the grains, which can affect their color and flavor.
Water
Water is a vital part of the brewing process, and the water chemistry behind your brew has a huge impact on its flavor. The hardness, mineral make-up, and pH level of water affect the mash and fermentation processes.
While homebrewers can usually calculate their water needs using simple trial and error, larger breweries should use water reports and water-quality testing to properly match their water profiles to beer styles and recipes. The most common water ions used in beer are carbonate (or bicarbonate), sodium, chlorides, sulfates, and calcium.
Chloride is a commonly added ion to give your brew a rich malty finish and to accentuate its mouthfeel. It also promotes stability during the mashing process.
Sodium is another important ion that contributes to the body and mouthfeel of beer. Typically, sodium levels in the 10-70 mg/L range are acceptable.
Sodium also has the potential to cause a metallic taste, so softened or highly alkaline water should not be used for extract brewing. Sulfates can balance out the sweetness and hoppiness of beers, but a ratio of sulfates to chlorides should be carefully calculated.
Hops
Hops are a major flavor and aroma contributor in beer. They add the desired bitterness, aroma and typical flavors to beer and act as a natural preservative.
In the brewing process, hops are added to the wort at several points. Adding them early in the boil destroys most of their essential oils, so you may want to add them later or use them as part of dry hopping.
Each variety of hop has different bittering and aromatic potential. The ratio of alpha to beta acids determines this.
Alpha acids are divided into three analogues–compounds of very similar molecular structures–that are called humulone, adhumulone and cohumulone. High levels of cohumulone in hops tend to produce a harsher bitterness and lower foam stability.
Because of this, brewers prefer to purchase pelletized hops. This allows them to transport the hops easily and offers an extended shelf life. It also prevents the lupulin glands from being exposed to oxygen during shipment.
Yeast
Yeast, which translates to “sugar fungus,” is the underlying force behind beermaking. It metabolizes sugar molecules to produce alcohol and carbon dioxide, allowing beer to be fermented and conditioned.
Unlike bacteria, yeasts do not require sunlight for energy production; instead they use organic compounds to fuel growth. Their metabolisms include metabolizing hexose sugars (glucose, fructose and maltose) as well as disaccharides (sucrose and maltotriose).
Modern brewer’s yeast, which is the most common species used to make beer, is part of a larger group of Saccharomyces cerevisiae yeasts, which can also make wines, spirits, fuels and medicines.
Brewers like a variety of strains to choose from. These vary in their temperature of growth and the way they work.
These differences affect how beer is made and how it tastes. For example, lager yeasts grow best at lower temperatures than ale yeasts. This makes lager beers more clean and crisp, while ales offer fruity and aromatic flavors.
