I know this was just recently asked, but I somehow forgot to save the answer, which I remember being "glass is best." What is the very best material for containers to store milk for (1) refrigerated storage, and/or (2) frozen storage and why. This question has come up several times recently on Parent-L and alt.support.breastfeeding. Rachael Hamlet Visit the Breastfeeding Advocacy Page http://www.clark.net/pub/activist/bfpage/bfpage.html