Controlling the pressure of the beer storage tank is one of the important contents to control the CO2 content of the brewed beer. Beer is produced by traditional fermentation methods. The CO2 contained in the beer is mainly produced by the fermentation process (including main fermentation and post-fermentation), while the saturation of CO2 mainly occurs during the storage process. Under the condition that the tank is closed, the CO2 produced by the fermentation relies on the adjustment of the tank pressure and the temperature of the fermentation liquid to achieve the purpose of controlling the CO2 content. According to the law that the gas is dissolved in the liquid, the higher the pressure, the lower the temperature, and the more the amount of dissolution until the saturation state is reached.
The tank pressure must be controlled according to the actual needs of the CO2 content, instead of being as high as possible, and care must be taken not to exceed the allowable operating pressure of the tank to prevent danger.
the traditional fermentation, tank pressure control should be based on the fermentation room temperature, high room temperature, fermentation liquid temperature is also high, the tank pressure can be controlled higher, and vice versa, can be controlled lower. When the post-fermentation room temperature is greater than 3 ° C (but not more than 5 ° C), the tank pressure can be controlled at 0.118 ~ 0.137MPa; when the post-fermentation room temperature is lower than 3 ° C, the tank pressure can be controlled at 0.078 ~ 0.098MPa;
the traditional low-temperature fermentation, after the fermentation tank is pressed within 3 days after sealing, it is best to reach 0.039 ~ 0.049MPa, the next 3 to 5 days must reach the control pressure specified by the process, otherwise the pressure increase rate is too slow, deal with The temperature of the beer, the sugar content of the beer and the time of sealing the tank are adjusted appropriately. If the age is longer, the boost rate can be slowed down appropriately, but the required pressure must also be reached within 10 days.
When the pressure exceeds the process specification, open the venting small cock and slowly discharge a part. Of course, it is most convenient to install the automatic safety valve on the equipment. When the tank pressure exceeds the specified pressure, it will automatically deflate and lower. It will automatically close when the pressure is controlled to achieve the purpose of automatically controlling the tank pressure.
in the case of post-fermentation room temperature is low (such as -1 ~ 1 ° C), the tank pressure control should not be too high generally 0.069 ~ 0.078MPa is appropriate, otherwise, because the CO2 saturation is too high will be in beer filtration, A large amount of foam is generated during filling, or it causes spillage, which affects normal operation and causes loss of beer.
For beer with a shorter age, the pressure control can be 0.019～0.029MPa higher than that of beer with long age. Because the amount of CO2 dissolved in the fermentation liquid has a certain relationship with the storage time, the drinking age is short, and the fermentation liquid absorbs CO2. The degree of dissolution and association is poor, and CO2 which is simply mixed (or pseudo-dissolved) easily escapes from the fermentation broth, and higher pressure control may be beneficial to the dissolution of CO2.
Record the pressure of each storage tank every day. When it is found that the pressure has changed greatly, find out the cause and take timely measures.