Due to the large size of fermenters, usually a few batches of wort can fill a fermenter. Therefore, we transfer the wort to the fermenters one by one, but the time to fill the tanks should usually be less than 20 hours.
Once the wort is in the beer fermenter, the yeast begins to multiply and produce heat. The temperature of the fermenter also rises. Therefore, the cooling temperature needs to satisfy the principle of low to high and then to the temperature of the full tank. Usually the full tank temperature should be about 2°C below the primary fermentation. Usually, the fermenter temperature should be about 2°C below the primary fermentation temperature. A lower fermenter temperature will prolong the natural warming time and slow down the yeast reproduction rate. Therefore, it will hinder rapid fermentation. At the same time, it will leave the beer at a low fermentation level. Conversely, a higher full tank temperature will accelerate yeast multiplication in the early stages. Too fast sweetening will reduce the metabolic function of the yeast due to lack of nutrients, which will affect the recovery of diacetyl. At the same time, it will prevent the production and saturation of carbon dioxide, which will destroy the taste and foamy character of the beer.