The following points should be paid attention to when using storage yeast:
For each recovered yeast, a label indicating the recovery time, yeast generation, and yeast variety must be attached to the yeast container;
Try to reuse and utilize the original yeast to prevent storing yeast for too long;
The number of generations used should be strictly controlled, generally not exceeding 8 generations. For factories that do not have conditions for yeast propagation, efforts should be made for self-selection and expanded propagation, or yeast should be purchased from external factories. Select strong yeasts from the yeast paste for propagation;
Regular quality checks should be conducted on stored yeast, including fermentability, viability, budding rate, agglutination performance, cell morphology, and bacterial contamination. If any issues are found, they should be addressed promptly;
In case of poor viability of stored yeast, the feeding method should be used to add yeast as much as possible, which means the freshly recovered yeast should be immediately returned to use after sieving and washing. This will not only correct the deficiency in data but also help reduce the lag period of yeast;
In order to solve the problem of yeast storage and usage, a sterile and low-temperature yeast storage room should be specifically set up near the main fermentation area, in addition to the recovery, cleaning, and storage of yeast. The yeast storage room should be equipped with a blue ice water container, which should have a capacity 2 to 3 times the total volume of the yeast storage container. Moreover, the ice water container without teeth should be equipped with water filtration (mainly sand filters);
The yeast feeder is usually also located in the yeast storage room. The feeder should be equipped with a mixing device (compressed air or agitator). The yeast can be sent to the feed tank using sterile compressed air or a mechanical pump.
