The fermentation in beer is a basic and the most important part of its development process. It depends on the temperature and the mixture of different ingredients. Moreover, taking into account the composition of the juice, the, pressure, how we add yeast, the oxygen...
During the fermentation step juice is added to the tanks for this purpose and mixed with yeast to convert the sugar in the juice into alcohol and carbon dioxide, which is the purpose of this process. There are two important stages, primary and secondary fermentation.
Primary begins when yeast is mixed with the must that is already cooled and encompassing the adaptive exponential growth of the yeast. We will control the maximum temperature for good results.
The secondary fermentation is based on tuning the beer before packaging and transferred to another vessel and is usually done after about 9 days of primary fermentation. The temperature in this phase is 15 ° C but depends on the temperature of the first phase, and thus should generally be between 5 and 10 ° C less than the first.
The type of fermentation is further divided into high or low, and the results are Ale beers (high) and Lager (low). Passing beer fermentation by low temperatures occurs in about 6 ° C and for this particular yeast that are at the bottom of the tanks. A popular top-fermented beer is pilsner.
While top-fermented beers are made with really high temperatures of 16 ° C on average. German beers or Ale are of such type fermentation.
Another type of fermentation is the spontaneous, without yeast added, usuin ghte yeast of the air. Hardly used now.
Alhambra Reserva 1925