3. Fermentation. Pure must flows through the pipes to a bottom of the fermentation tanks, which are called cylinder-conic tanks. After the must has cooled, yeast is added to the tank. For top fermentation beer the must is cooled to 64.4-71.6°F/18-22°C before adding yeast; for the bottom-fermenting beer – to 41-50°F/5-10°C.
After a day of the yeast laying a thick layer of foam is formed on the surface of the fermentation tank. This means that yeast successfully began converting sugar into alcohol and carbon dioxide. During the fermentation a lot of heat is produced, so the must require constant cooling, the temperature must be stable.
During the fermentation, brewers monitor the concentration of carbon dioxide in the tanks. When it reaches the maximum level, gas is discharged through special pipes. The fermentation stops after all of the sugar contained in beer is processed by yeast.
4. Maturation. In the previous steps, we got a new unfiltered beer which requires further maturation (is not applied to wheat varieties). For maturation, you need large stainless steel tanks. The process lasts from a few weeks to four months.
During maturation you need to maintain a stable temperature and pressure in the tank, these parameters should not change. In modern enterprises, the technological process is controlled with special equipment that can automatically adjust the temperature and pressure.
5. Filtration. After maturation, the beer passes another filtering with two different filters designed to remove large and small particles. After this the foamy beverage is absolutely transparent and ready for bottling.
6. Bottling. During the final stage of production, beer is poured into containers of different kinds. Before filling bottles, kegs,
barrels should be washed thoroughly. Then you should remove the air that got inside. Beer is a short-life beverage which requires sterile conditions. Without them, the shelf-life of the finished product is very small and its taste noticeably deteriorates. During the bottling glass containers are pasteurized in advance – slowly heated up to 149°F/65°C, which significantly extends the shelf-life of beer.
To systematize all of the information, take a look at the following diagram illustrating the sequence of steps.