Is it necessary to refrigerate olive oil after it has been opened?

It is not necessary to refrigerate olive oil at any time. Oil should be stored away from light and heat whenever possible, but it can be kept at room temperature without any ill effects. It is best used within one year, though it may last two years when stored properly.

Keep olive oil in a dark bottle to protect it from sunlight. If it's packaged in a light or clear bottle, transfer some to a dark wine bottle for everyday use, and store the rest of the oil in the back of a dark cupboard. Don't let oil sit out near a window, heating vent or the stove, where it can turn rancid.