I froze milk this winter in ziplocks: raw milk, 1/2 gallon per bag. I did find that after about 3 months or so the fat had separated off and stuck to the sides of the bag, but the milk still tasted fine. By the fourth month the consistency of the milk got kind of thick and it just didn't seem right. But by that time I was down to my last 2 bags, so I just tossed it. Can't wait for more! Harmony just kidded two days ago, so I will have good milk for my coffee soon!