Old flour gets rancid, generally from exposure to air in the canister or bag. You know what rancid smells like. You don't have to sniff close enough to get flour in your inhale, which like any other inhaled (inert) powder is bad for you. Obviously, ill stored flour can have pests, as well, though people have been eating flour with pest eggs in it since the beginning of grinding grain, and civilization advanced. I'd say no to that because of environmental chemicals and compounds. :) Realistically, there's little air in your packages, and they should be fine.

I agree

Whole grain flour spoils...white flour has had all the good for you stuff refined out....it's fine!!

Linda iis right that whole grain flour spoils faster, but while my kitchen remodel took four times as long as it was supposed to, my white flours in air tight but not full canisters went rancid, very obviously. There isn't nearly as much rancidity reacting oil in the white flour, but it’s there. Unpasteurized whole grain flour also can have wild yeast and various bacteria. Most require water to multiply, IIRC, but they might cause other kinds of spoilage, though I've never heard of that. It'll probably get rancid far sooner, which is noticable unpleasant. Although milling generally raises the temperature of flour, enough white flours have been recalled with e. coli that I wouldn't count on it being pathogen free, but that's a different issue. Baking generally takes care of all that.

Refined white flour will last quite a long time, and vacuum packed will keep it longer. As long as it tastes good, I'd use it, and figure baking or cooking will take care of anything else.

Of course, I've never kept white flour long enough for it to go "off". I have had whole grain flour get rancid, but if I grind my own, the wheat berries keep a very long time, appropriately sealed.

Annie

If I end up with a big bag of flour, I keep the excess in the freezer. It lasts a LONG time. I can't imagine white flour being much of a problem. Whole wheat gets rancid, which makes it taste bitter. You can usually tell by tasting it. It won't make you sick, just won't make quality baked goods. It has to do with the oils in the flour oxidizing (a product has to be exposed to air to oxidize) and since the oil in flour is in the germ, white flour doesn't have much to oxidize. If mold gets into it, it could possibly make you sick, but I don't know how likely that would be if it is kept dry, not very IMHO . . . I wouldn't sweat it as long as it smells and tastes OK. Rancid has a smell, like bad butter . . . I've had whole wheat flour go bad on me, but not white, so far . . .

I recently discovered a bag of white flour that i had forgotten about....easily 2 years old. It was fine...nothing in it to get rancid.

But i have had whole wheat flour and rye flour and corn meal get rancid...oh and crackers and cereal. I can small rancid miles away!

There is a trace amount of oil in white flour. It can get ranid. Rancidity is oxidation. Probably not enough air in the bag for it to get rancid. My full canisters didn't get rancid. The half empty ones did,

Thanks for the responses. Now the question is if my post-covid nose would recognize rancid. If anyone comes across anything rancid to send me please let me know. 😉

I read on a local group that we shouldn't buy flour that we can't use in 6 mths, tops. I buy 10-kg (22 lb) bags of flour, as it's much more cost-effective. I keep the large bag in a 5-gallon pail with the lid tight with my flour canister on the counter for regular use. I've yet to have anything go rancid.

As a matter of fact, last year I had lunch with my step-father and he gave me a 10-kg bag of flour that he bought, thinking he'd use it, and never did. So I took it even though I had just picked up a bag on sale at WM.

I like putting my bags of flour and rice on the balcony in the winter when I first buy them to kill any potential bug eggs. I have zero room in my freezer to store it.

It is not IMPOSSIBLE for white flour to go rancid, just very unlikely. FOAS, do you have someone who can do the smell/taste test for you? It's not subtle . . . think rancid butter . . . if you've ever smelled that. Another person has described it to me once as "dirty sweatsocks . . . " Honestly I think it is fine, some of this is splitting hairs . . .

As has been said, a little rancid won't harm you, and it's not that likely. You could dampen a little and see if it's bitter, if your tastebuds are okay. White flour should taste vaguely sweet. Rancidity is bitter. It's the smell of old, oxidized oil, if you can smell somewhat. If the kids can smell just ask if it smells bad.