If it smells good and tastes good, use it.

Save your cooking oil for bear baitings.

Hi. I just got a few boxes of unopened cottonseed oil from my work. Although it is about 1year past it's best before date. It is definitely unopened. I work in an oil refinement factory so I can vouch for its production quality. But any help would be great I have never used this oil before and don't know how it should taste or smell. Thanks.

Go buy a small bottle at the grocery store and compare the smell to the stuff in the boxes. As far as the OP goes, cooking oil takes on tastes of what you fry in iteven if it isn't rancid it can impart a bad flavor after it is used a couple of times. If you are asking the question, and aren't sure about the appearance, don't use it, it most likely won't make anyone sick from bacteria because of the high temps it is used at, but it won't make your food taste good either.

Well, I use frying oil as long as it looks goldish brown enough. I don't think you'll die from the bacteria in it since you're heating it.

I store mine in the basement where it's cool, I strain it through cheap coffee filters. Cooking potatoes will cleanse it slightly. Once you cook fish in it then everything will taste like fish. Usually 4-6 frys is all I get over a period of 4 months. When in doubt ,throw it out.

I don't think you will make your family sick as the heat of the oil would kill any active stuff in it. But the flavor may be off. Oil can oxidize and go rancid which would give an off flavor to things cooked in it.