Q. I have been buying previously frozen shrimp (unknowingly). When I got it home, I would clean them and freeze them again. We have been eating them without any problems. I’ve been told that you should not re-freeze shrimp

….. MaryAnn, Lombard, IL

A. The majority of shrimp sold in the United States have been previously frozen. The largest shrimp-producing countries are China, Indonesia, and Thailand, with some shrimp coming from Ecuador and Vietnam. Only a very small amount of the shrimp sold in the United States is from US waters. The general rule is to never re-freeze any item that has been previously frozen, though most people do with no problem. The problem occurs when food is left to defrost at an improper temperature. All perishable food should be kept below 40F. Fish and seafood should be stored at 33F. When perishable food is kept at improper temperatures, bacteria can grow. If the shrimp you have purchased has been handled correctly, you should not have a problem with re-freezing.