In the most simple of terms, brewing is the mixing of a starch source with water and then adding yeast to induce fermentation. Sounds simple, but the process can get a little complicated.
Step 1: Malting the Grain
Today, most beers use malted barley as the starch source for the brewing process. Malted barley is produced by soaking the barley grain in water to partially germinate the seed, and then drying it with the help of a kiln. After the gain is malted, it will be milled to expose specific parts of the grain for mashing, the next step.
Step 2: Mashing
In the mashing process, the milled grain is mixed in hot water to create a cereal mash. Complex carbohydrates are turned into simple sugars by enzymes found naturally in the milled grain. After this process is complete, the resulting sugary liquid is called the “wort.” The temperature of the wort may be raised to deactivate the enzymes at this stage. The wort is filtered from the grain and sent to boil. The type if malt used in the mashing process determines the color, flavor and aroma of the final product.
Step 3: Boiling
The wort then is boiled in a large kettle with the addition of hops. This phase of the brewing process is where decisions concerning flavor, aroma and color of the beer are made. The timing of the addition of hops into the wort effect the outcome of the final product. Hops that contribute bitterness need at least 60 minutes of boil time, where as, hops used for flavor and aroma are added in the last 15 minutes. After this mixture is boiled, the larger particles are separated out, the resulting liquid is cooled, and the yeast is added.
Step 4: Fermentation
During fermentation, yeast is added to the mixture to produce alcohol. There are three main types of fermentation: warm, cool and spontaneous. Warm, top, fermentation occurs at 59 to 68°F. These beers are typically ready to drink after a short maturation period but can be held and conditioned for many months. Cool, bottom, fermentation happens at around 50°F. The beer produced is kept at near freezing temperatures for at least a month to reduce the less desirable flavors produced during fermentation. During spontaneous fermentation, the wort mixture is allowed to pick up wild yeast and bacteria from the surrounding open air and ferment on its own.
In this day of modern technology, yeasts and fermentation styles (top-warm and bottom-cool) have lost a bit of there meaning. Most brewers use large fermentation tanks that are conical at the bottom to allow for easy disposal of particles formed during fermentation before conditioning.
Step 5: Conditioning
Conditioning can take various forms. Lagering, bottle conditioning, and secondary fermentation are common types of conditioning. Lagering is when the beer is kept at near freezing temperatures for more than 30 days to clarify the beer and reduce distasteful flavors produced in fermentation. Bottle conditioning is when the beer is allowed to ferment after being bottled, giving the beer natural carbonation. Secondary fermentation occurs when, after initial fermentation, the dead yeast and other potentially harmful debris are removed, and the beer is allowed to continue fermenting. It is also when additional flavoring agents such as fruit or herbs are introduced to the beer.
This conditioning process can take anywhere from a few weeks to several years depending on the goals of the brewer.
Step 6: Filtering and Packaging
Before the beer is packaged, it is filtered to remove any remaining sediments. Some styles of beer don’t go through the filtering process, especially wheat beers. The beer is then force carbonated and bottled or canned for our enjoyment.
Content provided by Jonathan Morgan, Martin Wine Cellar