An unopened container of peanut oil can be kept in the pantry for up to three years. Once the container is opened, the oil should be used within two years. For the best flavor, opened peanut oil should be used within four to six months.
Cooking oils should be stored in their original containers in a cool, dark place. Storing peanut oil in the refrigerator may extend its shelf life. If it solidifies in the refrigerator, let it stand at room temperature until it turns into liquid again. An unpleasant taste and smell are good indicators that peanut oil has gone rancid and should be discarded.