About 3~7 days. Under normal circumstances, the lactone tofu can be stored in the refrigerator for about 3~7 days, which can play a fresh-keeping role. However, if it is kept for too long, bacteria, molds and other microorganisms will grow, which will lead to changes in the color and smell of lactone tofu, such as black color and bad smell. In this case, it is not recommended to continue eating.