EnglishViews: 26 Author: Site Editor Publish Time: 2025-05-29 Origin: Site
Temperature is one of the key factors affecting beer fermentation. Different types of beer need to be fermented within a specific temperature range. For example, lager is usually fermented at a low temperature of 7-13°C, while ale is fermented at a high temperature of 15-25°C.
Too high a temperature will cause yeast metabolism to be too fast and produce undesirable flavors, such as too many aldehydes or esters; too low a temperature will reduce yeast activity, prolong fermentation time, and even cause fermentation stagnation. Therefore, the fermentation tank needs to be equipped with an efficient temperature control system and the temperature sensor needs to be calibrated regularly to ensure that the fermentation process is carried out under appropriate temperature conditions.
In the early stages of beer fermentation, oxygen is essential for yeast growth, but excessive oxygen can cause beer oxidation and affect the taste.
When the wort enters the fermentation tank, the dissolved oxygen content should be strictly controlled. It is generally recommended that the oxygen content be between 8-12 ppm to ensure healthy yeast growth without causing oxidation problems.
In addition, the entire fermentation process should try to avoid contact with air, such as using closed pipes to transfer wort and ensuring that the tank is well sealed.
During the fermentation process, yeast produces a large amount of carbon dioxide. If the pressure in the tank is too high, it will inhibit the activity of the yeast and affect the fermentation efficiency; if the pressure is too low, the carbon dioxide may escape too quickly, affecting the carbonation of the beer.
Therefore, fermentation tanks are usually equipped with automatic pressure regulation systems to ensure that the pressure remains within a reasonable range. For example, the fermentation pressure of ale beer is usually 0.1-0.3 bar, while lager beer may require higher pressure to control the fermentation process.
The health of yeast directly affects the fermentation quality of beer. Ensuring the best fermentation environment requires:
Use highly active yeast and regularly renew or cultivate fresh yeast. Control the amount of yeast added to ensure the appropriate yeast concentration in the fermentation tank to avoid fermentation too fast or too slow. Regularly recycle, clean and store yeast to prevent it from aging or mutation, which affects fermentation efficiency and beer flavor.
The cleanliness of the fermentation tank is directly related to the quality of the beer. Any residual yeast, protein or sugar may become a breeding ground for bacteria and affect the fermentation process. Therefore, a CIP (cleaning in place) system should be used for automatic cleaning, and the cleanliness of the fermentation tank should be checked manually regularly.
In addition, thorough disinfection should be carried out before and after fermentation. Steam disinfection, high-temperature water rinsing or chemical disinfectants (such as peracetic acid) can be used.
Oxidation is one of the main factors affecting the quality of beer, especially in the late fermentation and maturation stages. The fermentation tank must be well sealed to prevent the entry of outside air.
In order to ensure the best fermentation environment, in addition to daily maintenance, data monitoring and analysis should also be carried out, including:
Fermentation temperature curve, observe whether the temperature change is in line with the set range.
Carbon dioxide and oxygen content, to ensure that the fermented beer is not oxidized.
Alcohol concentration and final sugar content, to determine whether the fermentation is complete.
Flavor evaluation, to ensure that the fermentation environment does not have an adverse effect on the taste.
Using a modern fermentation management system, these data can be monitored in real time to ensure the stable quality of each batch of beer.
