How should breweries store yeast?

The preservation method of yeast is directly related to the quality and flavor of beer. The following is a detailed introduction of Tiantai on the preservation of beer yeast, which aims to help production companies master the correct preservation techniques to ensure the vitality and stability of yeast.

In the beer production process, the proper preservation of yeast is as important as the separation and cultivation. Improper preservation may cause yeast mixing, aging, denaturation, mutation, and even death, thus affecting production efficiency and quality. The preservation of beer yeast is mainly divided into two categories: pure strain preservation and production yeast preservation.

Common methods for pure strain preservation

• Solid slope method: simple and practical, suitable for the preservation of beer yeast.
• Liquid test tube method: also suitable for the preservation of beer yeast.
• Liquid paraffin slope method: although less used, it is also an effective preservation method.
• Vacuum freeze drying method: less used in the beer industry, but has the advantage of long-term preservation.

Yeast preservation strategies in beer brewing

1. Hansheng tank preservation method Hansheng tank preservation method is commonly used in large breweries. After expanding the culture of pure strain yeast in Hansheng tanks, most of the fermentation liquid is separated, and the remaining yeast is added to sterilized wort and cultured at 2-4°C. Regularly changing wort and checking yeast quality will help maintain the stability of strains and ensure the consistency of beer taste.
2. Method for preserving squeezed yeast In a low-temperature environment, squeeze and dehydrate the cleaned yeast mud, crush it into small pieces, and then store it at low temperature. Appropriate addition of ice water or 2% potassium dihydrogen phosphate solution can extend the storage time. When using, make it into mud with sterile water.
3.  Method for preserving mud yeast Soak the cleaned yeast mud in 0-2℃ sterile water, change the water 2-3 times a day, and it can be stored for up to 5-7 days. This method is simple and easy and is suitable for yeast used on site for short-term use. If the storage time needs to be extended, it can be placed in a 10% sterile sucrose solution and stored at a low temperature.
4. Fermentation broth preservation method Take out the fermentation broth at the peak of fermentation, quickly cool it to 2-4℃ for storage, and use it to inoculate the next batch of wort fermentation. Strictly control the temperature, ventilate, and supply oxygen in time, and the storage time can reach 2-3 weeks.

In short, yeast preservation is an important link that cannot be ignored in the beer production process. By mastering the above preservation methods, companies can effectively ensure the quality of yeast and provide strong guarantees for the production of high-quality and stable beer. In actual operation, appropriate preservation methods should be selected according to production needs and conditions to ensure the vitality and stability of yeast, thereby improving the overall quality of beer.