I've told this story before, but here I go again... I had some bread flour in a plastic container a few years ago. It had been in there for maybe a year? Maybe 18 months. It smelled like plastic when I went to use it. An awful smell, too. Not like brand new plastic (that you wouldn't want in your food either), but a super chemical-like smell. I know it wasn't the flour gone bad because I've since had the same flour sit around the same length of time, but in a glass jar. The flour remains good in the glass. I have other plastic breaking down and smelling bad experiences as well. For one, Nalgene bottles I used to use backpacking that "turned" and went yellow and releasing a plastic chemical odor, and those aren't just your standard ol' crap plastic either. I've heard even Lexan bottles go bad, and that plastic is designed for hot food to not break it down (you know how some plastic can turn colors from chili or tomato sauce in them). I think the aforementioned 6 months cap is a good rule. Personally, I don't leave anything in plastic anymore that comes in a plastic container. I don't know how long it has already sat in the original plastic container, so there's no solid way for me to judge six months. I don't rush to move it into a new container. It's not a crazed paranoia thing, but I do try to get to it sooner than later. I know the Briar Blues fella uses food grade plastic bags he vacuum seals to age his tobacco for a short period (or at least he does in his youtube videos), but even that seems unnecessary to me. Glass all the way for me.
