Remember if you use ziplock bags and wash them, wash them very well in very hot water and they have to air dry completely to be safer for reuse. I had to take a class course one time and we had to do several different experiments on food safety. There was a class of 22 of us and we were paired in two's. Everyone had different ones to do, then we had to do bacteria tests on each one. The reuse of the ziplock bag was not good.