Beer making is a very simple process though a lot of new brewers tend to get put off or scared away by the multitude of terms used. I hope that this post will help to explain in simple words hows our favorite beverage is produced.
The key ingredient is grain, whether it be Barley, Wheat or even Rice (think rice beer from North East India)! Traditionally though, it’s Barley and sometimes Wheat. The sugars in the grain, mainly Maltose, are what gets consumed by Yeast, and the byproduct is alcohol and carbon dioxide.
First the grains are “Malted”. This process involves allowing the grains to germinate, and then drying them in a kiln. The germination process allows the seed to break down it’s reserves in preparation for the seedling. It creates a number of enzymes that will convert the starch into sugar. Drying the germinating seed in a kiln stops the germination process before the starch conversion, leaving the starches for the brewer to extract as he needs.
There are two types of Malted grains that brewers work with – those that need to be mashed and those that don’t. The Mash process is what converts the starches into sugar. The malts that do not need to be mashed are what brewers refer to as Specialty malts. These malts go through special processes where the starches are converted to sugar using heating techniques. These just need to be steeped in hot water to release their sugary goodness.
Once a brewer has acquired the malted grains he wishes to use, the next step is crushing or “Milling” the grain. There are various types of mills available to the Homebrewer today. Hand mills need a lot of manual labour to crush the grains. There is however another type of mill that uses a power drill to rotate two rollers between which the grain gets crushed.
Once crushed, the grain is mixed with water at varying temperatures in a process called “Mashing”. The vessel used for this process is called a “Mash tun”.
The mash tun has a perforated bottom on which the grains rest. There is a tap to extract the liquid below this false bottom.
During this process, the starches in the grain are converted to sugars. The different temperatures used during mashing enable the brewer to extract simple or complex sugars depending on the requirement of his recipe. A typical mash temperature is between 65°C to 75°C.
There is also a process called step mashing which involves holding the mash temperature at 50°C for a Protein rest, then raising the temperature of the mash to 65°C and holding for Beta Saccharification, raising and holding at 70°C for Alpha Saccharification, and finally Mash out at 75°C. I will go into further detail on this in future posts for the sake of keeping this post as simple as possible.
Once Mash out is achieved, and the wort is being moved to the boiling vessel, the brewer may chose to sprinkle additional water at 75°C over the grain bed to extract any leftover sugars from the grains. This is called Sparging. Note: Wort is the name used for the sweet liquid that is the result of mashing.
The move mentioned above where the wort is being drained from the Mash tun to the boiling vessel is called Lautering. The perforated bottom mentioned earlier comes in use here where it holds the grain bed in place and allows the liquid wort to drain from below the grain bed into the boiling vessel/ kettle.
Once the wort has been strained from the grains, it is boiled (typically 60 mins) with hops and/ or other adjuncts depending on the recipe. The boil process helps separate the proteins from the wort and helps extract the resins from the hops. Hops are the flowers of a vine and they contain the resins and essential oils that give the wonderful flavour and aroma to beer that we all love.
At the end of the boil, a lot of brewers like to create a whirlpool effect to ensure that the solids that have formed during the boil, and leftover hops accumulate at the center of the boiler, and so do not get added into the fermenter.
Once the boil has been completed, it is very important to drop the temperature of the wort to what is known as the pitching temperature. At this stage the wort is susceptible to infection from bacteria so the faster this is done the better. The pitching temperature is the temperature at which the fermentation will be carried out, and so, is also the temperature at which the yeast will be added to the wort.
The fermentation vessel used by home brewers is either a Carboy (think a 25L mineral water bottle), or a large food grade plastic bucket. The yeast is added to the wort (pitched) and then gets to work. It converts the sugars in the wort to alcohol and carbon dioxide. Depending on the type of beer, the type of yeast used as well as the fermentation temperature will vary. Ales use a top fermenting yeast, and are fermented between 15°C to 20°C. Lagers use a bottom fermenting yeast and maintain between 11°C to 15°C. Temperature control is very important during fermentation. If there is major temperature variations during this stage, it will result in “off” flavours in the beer.
During fermentation a thick foam forms on top of the beer, and is known as Krausen. It contains yeast and proteins from the wort. The thicker and bigger the krausen, the more forceful the action of the yeast. It depicts the high point of the fermentation process. As the yeast eats through the supplies of sugar, the krausen subsides.
Once fermentation is complete, the resulting beer is flat. This beer is then bottled, or kegged. If putting into kegs, it is a very simple process to force carbonate the beer before serving using CO2 cylinders. If not kegging, a lot of brewers bottle the beer with a little bit of added sugar. This sugar is then consumed by the left over yeast and the resulting carbon dioxide carbonates the beer.
Once bottled/ kegged home brewers leave the beer to “condition” for a period of time. This allows the suspended yeast particles to settle to the bottom, and also any off flavours to mellow out and become palatable.