How do I keep oil from going bad?

I tend to buy cheap cooking oils. Not that I have cheap tastes, mind you. I’d love to spend a good $50 on olive oil.

Thing is, though, I use so little oil when I cook that it goes rancid before I use much of it. I’m constantly throwing out 3/4 full bottles of canola, peanut, olive, and sesame oils. If I want to cook, let’s say, Chinese, I’ll have to buy a whole new bottle of peanut oil for the occasion because chances are the mostly full bottle I already have has already gone bad.

Is there any way I can preserve a given bottle of oil for, say, more than a year?

More than a year? Maybe. Do you refrigerate them? While some oils (like olive) will solidify in the fridge, I don’t find that much of a problem. I do store them in wide-mouthed jars, though, so I can scoop out what I need with a spoon. I go through mine within a year, though, so I don’t know if they’ll last longer than that.


I am so sorry I quoted the OP in the first reply. That’s one of my pet peeves, and it was purely accidental.

I’d settle for two months, actually.

Olive oil seems like the least of my worries. Peanut and sesame seem to be the worst.

I understand that rancidity is more of a problem than bacteria, and it’s caused by oxidation. I keep things tightly capped, so I’m not sure why they go bad so fast.

I’m sorry you brought this up I will have to rethink my oil usage.

I would refrigerate it, maybe decanted into a smaller, tightly closed container.

The best you can do is keep a tight lid on it and keep it in the fridge. I don’t think peanut or sesame oil solidify at that temperature, but I’m not sure. You could also put a small amount in a seperate container and then freeze the rest, and just make sure to take out some more when you get low on the thawed amount.

Sesame is tricky, but peanut oil should last a while. Certainly more than two months, even in a clear plastic bottle in your pantry. Are they exposed to light and fluctuating or high temperatures? That can make them go rancid sooner.

Not light, but my kitchen is little bigger than a walk-in closet. When I cook, it heats up pretty fast.