Re: bottle refusal... not in the way youd think.
The metallic taste is from lipase. I doubt anyone is going to do any more rigorous testing than that for you. You can donate milk with excessive lipase. If you get 2 days before your milk tarts to turn, then you can feed your baby the milk that you pumped the day before without scalding it. You will need to scald the milk you pump on Friday, however. Freezing destroys immunological elements in the milk even without scalding. So if you were giving your baby frozen milk, then there won't be a huge compositional difference if you scald it first. Scalded, frozen breast milk is still far superior to formula. As long as you nurse your baby when you are with him, then you needn't worry about feeding scalded milk while you are apart. Lots of women need to scald their milk.
It sounds like your baby is rejecting bottles in addition to the lipase problem. Perhaps try a variety of different styles of sippy cups. My son switched over to a sippy cup at daycare sometime between 8-9 months. Or give him a cold washcloth or teething ring before the bottle if you think it could be teething.
K. Sophia - Mama to my little lactivore, the amazing Mr. X (11/10).