I have 2 separate hanks of natural hog casing in my fridge. When I am finished using them I store them in container, drained with 1/2 cup salt and a cap full of vinegar. Today went to get them and one container had 2 small pieces of mold floating on top. The water was also murky. No smell and no discoloration. I rinsed them several times and the water cleared up. The other container was fine. What may have caused this? It's a new hank that I flushed several weeks ago. My first guess is the container was/is not air tight. Also do y'all think they are safe to use?