There are usually four methods to add yeast into the tanks.
The dry adding method involves putting a suitable amount of cool wort into the yeast tank and measuring the required amount of yeast (0.6%-0.8%). The yeast is then added to the yeast tank, and the yeast and wort are mixed evenly. Finally, sterile compressed air is used to pressurize the yeast into the fermenter and mix it with the wort.
The wet adding method involves putting a portion of 10°C-15°C wort into the yeast tank, followed by adding the required amount of yeast. The temperature is maintained at 10-12 hours to allow the yeast to regain its activity. Once the yeast starts budding reproduction, sterile compressed air is used to pressurize the yeast into the fermenter and mix it with the wort.
The cutting method is mainly used when there is insufficient yeast available on the production site.
In continuous adding, the yeast is added throughout the wort process to ensure even distribution in the yeast tank. The yeast amount is controlled using a wort pump with VFD control.