The Brewing Process

As part of this class we have learned a great deal about the brewing process as a whole.  Below is a description of my understanding of brewing beer:

The brewing process occurs in several stages including malting, brewing and fermentation.  Each stage is important in developing the flavor, aroma and appearance of a beer.

The malting stage involves the germination of barley grains.  Adding water and heat to the barley grains initiates the germination process.  Germination is when the enzymatic proteins of the seed are activated in order to break apart the starches within the grain.  Starches are long chains of smaller sugars such as glucose or maltose.  The enzymes break the starch strand down into smaller sugars that can be used in the fermentation process.  The germination process occurs over the course of approximately one week and then the seeds are kilned and dried out to stop the germination process.  At this point, the grains can be roasted for the development of further coffee or roasted flavors.  For many home brewers the malting process can be skipped by using malted extracts.  This is concentrated syrup that has been developed from the malting process.

The brewing process involves the steeping of the malted grains in water in order to remove the sugars that were developed throughout the malting process.   The grains and water are brought to a boil for approximately an hour and hops or specialty grains can be added throughout the boil in order to develop the flavor of the beer.  This new mixture is called the wort.  After the boil, the wort is strained, often in a lauter tun, in order to remove the grains.  The wort is then quickly cooled in order to precipitate all of the unwanted proteins within the the mixture.  The wort is then transferred to fermentation tanks. during this transfer the wort is aerated.

When the wort is finally in the fermentation tank, the active yeast is added to the mixture.  This is when the fermentation process begins.  The yeast will utilize all of the sugars that were developed in the malting process in order to grow and multiply.  This growth is done both aerobically (with oxygen) and anaerobically (without oxygen).  Yeast grows aerobically first, utilizing the oxygen that was added to the wort in the aeration process.  Anaerobic growth occurs after the yeast has utilized all of the oxygen within the wort.  The byproduct of the anaerobic growth is ethanol, which makes the beverage alcoholic.  The fermentation process can last up to three weeks time in which the beverage reaches its desired alcohol by volume.  Once the beer has fermented, it is conditioned to remove the larger proteins and can be filtered in order to remove the yeast.  The beer is then either kegged or bottled, and stored.

The entire process lasts approximately four weeks depending on the beer style that is being brewed.  The malting process is often the main difference between the small and larger scale breweries and home brewers.  The larger scale brewers develop their own malt combinations for brewing.  On the other hand, many home-brewers choose to skip the malting process because it is easy to find malt extracts at home-brew stores.  When we brewed for this class, we used a malt extract instead of malting the grains ourselves.  We also brewed much smaller batches of beer than many of the commercial and smaller scale breweries we have seen thus far on this trip.