Last week I made several gallons of chicken stock from a bunch of chicken backs I bought at Whole Foods. It's my second time making stock. The first batch was really great, a little cloudy but otherwise no problems. I more or less followed a standard recipe, I'm not sure which one at the time but nothing weird.
The stock at the time of cooking smelled a little bit off. I just defrosted a ziplock bags worth today and it smells distinctly musty. There is an odor of good stock in there but there is also a generally not that great smell. Doesn't smell rotten exactly but doesn't smell good.
The only thing I can think I did wrong is maybe not skim it effectively. I'm not sure I did a much better job of skimming the first time and it went fine, but otherwise, I'm really not sure what I did.
I'm assuming the smell should be like good chicken soup? Is there anything I could try to resurrect this batch? What should I do different the next time?
Stockless in Boston.