Q: My roommate went away for a week and asked me to keep an eye on his belongings. What should I do with perishable items with approaching expiration dates?

A: If the item will still be edible when the owner returns, albeit not fresh, you should leave it for him. This is especially true of homemade food, since a person prefers his own food to that of others (Pischei Choshen, Pikadon 2:[90]).

If the food will spoil, you should notify the owner. If you are unable to contact him, you should try to sell the food, if you are able to, as a form of hashavas aveidah (C.M. 292:15).

If you made no attempt to salvage the food and it spoiled, there is a dispute whether this is considered negligence (see Mishnah Berurah 443:12).

You are allowed to use the proceeds of the sale meanwhile, and therefore are responsible for the money as a shomer sachar. If you use the money, you are fully liable as a borrower (292:19).

Even if the food already spoiled, if the container or pot is one that might get permanently ruined, you should empty the food from it (292:16).