In China, the vast majority of breweries today use conical fermenters for beer fermentation. The tank itself is equipped with a cooling device, which can easily control the fermentation temperature; the conical tank is easy to operate, saves labor, and is easy to clean, and can also recover yeast. Many large breweries install conical tanks in the open air, which can save space; in craft beer, we generally don't use such large equipment, just put them indoors.

The so-called "one-pot fermentation" means that the entire fermentation process is carried out in a conical tank, and the pre-fermentation and post-fermentation are not strictly divided, and the production time is shortened compared with the traditional process. Next, we will introduce the operation method in detail.

Common lager fermentation process operations

The yeast inoculation temperature for lager fermentation is generally 6-10°C, and the maximum fermentation temperature is 12°C. The time from inoculation to sealing is about 5-7 days. Carry out canning when the sugar content drops to 3.8-4.2°P. After the pressure rises, keep the tank pressure at 0.12MPa, keep the temperature up to 12°C and keep it for 5-7 days to reduce diacetyl.

Afterwards, the temperature was lowered to 5° C., kept for one day, and then lowered to 0° C. again. The cooling rate is different at different stages. In the stage of 12°C-5°C, the cooling rate is 0.3°C/h, and in the stage of 5°C-0°C, the cooling rate is 0.1°C/h. The post-ripening stage of lager fermentation is generally 5-7 days.

Common ale fermentation process operations

The inoculation temperature for ale fermentation is generally 16-18°C, which is higher than that of lager, and its highest fermentation temperature can reach 20-23°C. It is about 1-1.5 days from inoculation to sealing, and the time is relatively short. Also seal the can when the sugar content drops to 3.8-4.2°P, keep the tank pressure at 0.12-0.15MPa after the pressure rises, keep it and count it for 5-6 days after the temperature rises to 20°C, and reduce diacetyl.

The cooling process of ale fermentation is also to drop to 5°C, stay for one day, and then cool down to 0°C. In the stage of 20°C-5°C, the temperature is lowered at a rate of 0.3°C/h, and in the stage of 5°C-0°C, the temperature is reduced at a rate of 0.1°C/h. Store at low temperature for 5-7 days, and the beer will mature.

Controlling different fermentation temperatures has its own advantages and disadvantages. When low-temperature fermentation is used, the yeast produces less by-products during the fermentation process, the taste of the beer is better, and the foam is in good condition, but the fermentation time is long; when high-temperature fermentation is used, the fermentation speed of the yeast is faster, the fermentation time is shorter, and the equipment utilization rate is higher. High, but more by-products are generated, and the taste of beer is poor.

Lager is generally fermented at 8-12°C, and ale is fermented at 16-20°C. In addition, pay attention to the control of winter temperature.

health

Hygiene plays a vital role in the quality of beer, pay attention to aseptic operation when inoculating yeast or dry hopping. Hands should be disinfected when opening the manhole, and the surroundings of the manhole and the outer packaging for yeast inoculation should also be cleaned and disinfected. The disinfectant uses 75% alcohol and sprays it with a watering can. Be careful not to use an open flame when disinfecting.

fermentation pressure

The fermentation pressure of lager beer is generally controlled at 0.12MPa, and that of ale beer is 0.15MPa. The fermentation pressure mainly depends on the final taste requirements of the product. The higher the pressure, the lower the temperature of the liquor, the more fully the carbon dioxide dissolves, the stronger the mouth-killing power of the beer, and the richer and longer-lasting foam.