2. Principle: Celery can be kept in the freezer for the longest time because no bacteria can survive at extremely low temperature, especially the sub-zero temperature in the freezer. However, because celery itself is in the state of root, it is difficult to cut and thaw if it is directly frozen, so it should be cut into small pieces that can be directly cooked in the pot, and then directly fried when it needs to be cooked. It tastes good.