How Long Can You Keep and Reuse Peanut Oil to Cook?

Preparing food in restaurant kitchen


Many cooks, whether at the professional or amateur level, use peanut oil for cooking with high-temperature methods, such as deep-frying. The popularity of peanut oil comes partially from the health benefits it offers, but its clean taste and high smoking point also makes it resistant against spoiling early and, as such, easier to save and reuse. If your kids like chicken tenders, try frying them in peanut oil and serving them with ketchup or a creamy dressing.

Peanut Oil Benefits

Unlike many other cooking oils, peanut oil does not absorb any flavor from foods cooked in it, making it possible to save and reuse without tainting the flavor of foods cooked later on in the same batch of oil. Additionally, peanut oil offers several health benefits. Peanut oil has a large amount of unsaturated fats but few saturated fats. This cooking oil also contains vitamin E and phytosterols that benefit the heart, but lacks trans fats and cholesterol.

Storage and Shelf Life

Unopened peanut oil lasts a year or longer, but opened peanut oil safely lasts four to six months before turning rancid. All oil eventually oxidizes and turns rancid as it ages, and rancid cooking oils have a negative effect on taste and health. Extend the shelf life of peanut oil by storing it in a cool, dark place, preferably the refrigerator. Seal the container of peanut oil as tightly as possible to minimize exposure to air during storage.

Reusing Peanut Oil

Overheating oil during cooking increases the likelihood of early spoiling, but peanut oil has a high smoking point of 447.8 degrees F, meaning that it overheats less easily than olive oil and many other common cooking oils. You can reuse peanut oil several times within the six month storage period, but sterilize it before each additional use by allowing it to reach 350 degrees F before adding any food.

Types of Peanut Oil

There are two main types of peanut oil. Refined peanut oil, often used in fast-food chains within the United States, goes through a refining, bleaching and deodorizing process. This process removes the allergic protein component of the peanuts. As a result, even individuals with a peanut allergy can typically consume food cooked in refined peanut oil. Gourmet peanut oil, on the other hand, does not go through a refining process and contributes a peanut aroma and flavor to the food as it cooks. Gourmet peanut oils usually contain high levels of vitamin E and phytosterols.

Peanut Oil Substitutes

If choosing a peanut oil substitute for deep frying, choose a cooking oil with a higher smoke point. The smoke point marks the temperature at which an oil begins smoking and decomposing. Corn oil, canola oil, soybean oil, sunflower oil and safflower oil all have higher smoke points than peanut oil. If using oil for skillet cooking or a relatively low-heat cooking, you may substitute any vegetable oil in place of peanut oil for most savory dishes. Olive oil, however, makes an especially healthy substitute since it, too, contains monounsaturated fatty acids that lower your risk of heart disease.