MIL was watching DS tonight and gave him BM from the freezer stash. She said he wouldn't touch it, so I gave it the smell test and it had this horrid metallic smell-- not spoiled or freezer burn. I have no idea how she thawed it. I am now worried that I have nearly 400 oz of bad milk. They are stored in BM bags in a locked stand up freezer (so it should be good for 6-12 months.) Help please?!