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?

[QUOTE=tdn]
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?
[/QUOTE]

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.

GAH!

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

[QUOTE=WhyNot]
More than a year? Maybe.
[/QUOTE]

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.

[QUOTE=tdn]
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.
[/QUOTE]

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.

[QUOTE=WhyNot]
Are they exposed to light and fluctuating or high temperatures? That can make them go rancid sooner.
[/QUOTE]

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