According to the FDA food code, there are two main options: If the fluid is below 41°f initially, you can safely leave it sitting for four hours before it must be discarded. If it didn't reach above 70°f and was below 41°f, to begin with, then it can be kept out for six hours. Once the soup or sauce has cooled down thoroughly, it can be stored safely in the refrigerator for up to 3-days, to be reused.