I know that whole wheat flour includes the oily bits of the grain, and thus tends to go rancid if you let it sit long enough. Back in the day when I used to bake bread a lot, I went through whole wheat flour fast enough that this was never a problem.
Nowadays, I don’t bake bread as much, and as such, I tend to buy whole wheat flour in small amounts when I bake. At some point, though, I must have bought a 5 pound bag of it, because I just found it in the back of one of my cupboards. I pulled it out, thinking it must be bad, because I don’t even remember buying it - it could be as much as a year old.
I opened the bag. Doesn’t smell rancid. I tasted a bit of it. It tasted fine.
Come to think of it, I never remember flour tasting or smelling rancid.
So what’s the deal here? Is it somehow rancid and I can’t tell? If I bake with it, will I end up with icky tasting bread? Or is this another old cooking adage that is no longer valid?
I know the first time I baked bread, back when I was 14 or something, it came out totally foul and inedible. In hindsight, I think there were two problems. First, the yeast was many years old, and dead. Second, the flour was many years old, and rancid. (At 14 I had no idea what flour should smell like, so the nasty rancid odor didn’t tip me off).
You say your bag of flour is as much as a year old. That may not be long enough for it to go rancid under the conditions of a cool, dark, dry cupboard. Leave it there another three years and see how it is.