The MICROBE-LIFT products, such as the liquid bacteria, will remain viable once they thaw, if frozen. However, they will lose some viability, about 10%, with each freeze/thaw cycle, so it is better if they do not freeze at all. The bigger problem is excessive heat in storing live bacterial products. You should be able to store the products in the garage for the winter. The ideal storage temperatures are between 40-105ºF.