Peanut oil shelf life, some used some virgin

Once opened cooking oils suffer from oxidation rather quickly and go rancid. Still safe, but tends to impart a less than desirable flavor and aroma to foods. If it doesn't give an off odor it's still good to go. You'll know if it's gone bad...rather offensive odor. Just don't open a sealed container to smell it, unless you plan on putting it to use soon afterwards and just need to make sure it's still good...once opened the clock is ticking, because you let air/oxygen into the container. You're doing the right thing by storing in a cool, dark place.

We had a unopened 5 gallon plastic jug of peanut oil that was dated for 5 or 6 years earlier...I opened it and gave it a little whiff...it had gone south...may have been a damaged seal on the lid, though.

Eric