Beer is defined as: an alcoholic drink produced by wort fermentation. A very brief description which requires additional explanation. Let’s go over the brewing process step by step.
To brew beer at least the following 4 ingredients are required:
- Brewing water having drink water quality
- Malted barley: Malt containing amylase, a digestive enzyme
- Hops: Hops contribute a bitterness that balances the sweetness of the malt and hops extends the storage life
- Yeast: a micro-organism that runs sugars into alcohol and carbon dioxide
Step 1: Mashing
Mashing is the process of combining a mix of milled grain, known as the grist with water, and heating this mixture up with rests at certain temperatures up to 78°C to allow enzymes in the malt to break down the starch in the grain into sugars, typically maltose. The sugar mixture is called wort.
Step 2: Wort separation
Wort separation is the separation of the wort containing the sugar extracted during mashing from the spent grain. The remaining malt rests are called ‘bostel’ and are used as cattle feed. The objective of wort separation is producing clear wort.
This part of the process takes about 2 hours.
Step 3: Wort boiling
After the wort separation process the clear wort is boiled about 2 hours to ensure its sterility. During the boil hops are added which contribute bitterness and flavours the wort. Different types of hops have a different aroma and taste. By using a certain type of hops one can generate a wide variety of flavours. (e.j. bitter, fruity, …)
Step 4: Fermenting
After the boiling process the wort is cooled down to a temperature of around 20°C. When the brew is pumped over from the boiling kettles to the fermentation tank aerated yeast is added. The actual fermentation process consists of 2 stages:
- During the first stage the yeast multiplies itself, using all the carbon dioxide.
- During the second stage the sugars won from the malt are metabolized into alcohol and carbon dioxide. The used yeast creates flavours and aromas which add to the final taste of the beer.
Step 5: Conditioning
When the fermentation process is completed the new beer ripens several weeks. During the conditioning process several flavours are generated causing a cleaner and more tasteful final product. After conditioning the beer can be drunk.
Step 6: Filtering
After the conditioning process most beers are filtered to give it its shine and brilliance. The beer is separated from the remaining yeast and other rests (like enzymes) which contributes to its clear appearance. Filtering doesn’t spoil the taste: by removing the yeast other flavours like hops (bitter) even add to the final taste.