While millions of people around the world consume beer on a daily basis, few really know what it takes to brew their favorite beverage. Here’s an overview of the beer-making process.
Malting
It all begins with the malting of the grain. During malting, the grain's natural germination process is simulated by moistening it at cool temperatures that allow it to sprout. As the kernels germinate, enzymes within the grain break down the hard, starchy interior of the grain, converting it to soluble malt sugars (called maltose). After several days of germination, the grain is heated and dried (a process called “kilning”), effectively halting the germination process. The barley is now called malt. A portion of this malted grain may also be roasted to various depths of color and flavor in order to create different beer styles.
Mashing
Mashing is the process during which the malted grain is steeped in hot water in a vessel called a mash tun. Before being added to the mash tun, the grain husks are cracked in a grain mill. While steeping in the mash tun, the complex maltose sugars in the malted grain are broken down by enzymes already present in the grain. These soluble sugars are easily dissolved –or liquefied- in the hot water. The sugary-sweet liquid “wort” is then drained away from the grain bed and transferred to the brew kettle to be boiled.
Boiling
The wort is boiled for up to two hours. During the boiling process, hops are added to the wort to provide bitterness, flavor and aroma. What types of hops are used and how long they are boiled is determined by the style of beer the brewer is making.
Brewers of very pale and light-bodied beers also use other cereal grains –in addition to barleymalt- to achieve the desired lightness in their product, such as corn or rice. However, corn and rice cannot be malted like barley, so they must be gelatinized in a cereal cooker in order to make their natural sugars more easily soluble in water.
Fermentation
After boiling, the wort is cooled down quickly and the hops are filtered out as it’s transferred to a fermentation vessel where yeast is added, to the wort. The yeast consumes most of the grain sugars in the wort, producing ethyl alcohol and carbon dioxide in return. The primary fermentation process typically lasts about a week.
Aging / Conditioning
After fermentation is over, the beer is transferred from the primary fermentation vessel to a secondary aging vessel called a conditioning tank. Ales are typically conditioned for a shorter period of time (1 to 3 weeks); lagers are typically cold conditioned for longer periods of time (4 to 12 weeks).
Clarifying
Even after lengthy conditioning, the beer may still be somewhat hazy due to yeast cells and protein molecules. The most common method of clarifying beer is by sterile filtration. The is pumped under pressure through a filtration system where virtually all particulate matter is removed from the liquid. When a crystal clear beer is not desired the brewer will allow his beer to clear by natural sedimentation (called “bottle-conditioning”).
Pasteurization / Packaging
Pasteurization is necessary to stabilize the beer as it is packaged for sale to the public. Pasteurization takes place after just after the cans and bottles are sealed (kegged beer is typically not pasteurized and, therefore, must be kept refrigerated at all times). Heating the cans and bottles up to 180 F. effectively kills all microorganisms that may be lingering in the beer.
