How Often Should You Change The Oil In Your Deep Fryer?

There are plenty of ways to get a crispy coating on your food's exterior, but for that rich flavor with the perfect crunch, it's best to reach for the deep fryer. Food prepared in this way is submerged completely in hot oil (essentially pure fat), which interacts immediately with the food's surface to crisp it up. Its hot temperature turns the moisture within the food to steam, cooking it thoroughly. But for the best fried food, you have to keep the oil clean, which means making sure you change it out when necessary.

How often you should change your oil depends mostly on what you're deep frying. If you're dealing with non-breaded vegetables, you can get more from your oil and only need to change it every six to eight uses. If you're frying meat with no breading, such as chicken wings, you can get three or four uses from each batch of oil. But frying something like fish that's loaded with breading or batter means you should change it after just two uses. Stick with a high-smoke-point, neutral oil, such as canola or sunflower oil, when frying. Anything with a low smoke point, such as extra virgin olive oil, will need to be discarded after as little as one use.

Reusing your deep fryer's oil is a common and safe practice, but the above guidelines are general rules of thumb. They can still vary, so it's best to look for signs that will tell you when your oil needs changing. The most obvious sign of old oil is smoke; if your deep fryer starts smoking before you've even begun frying, it means it's reached its smoke point sooner than it should, likely due to impurities from having used it for too long. Smoking oil can also be dangerous, so discard and replace it immediately.

Check your oil's color frequently. Fresh oil is clear, and the more you use it, the more the resulting impurities turn it cloudy, dark, or murky. If you can't see through it, it's time for a change. Oil should generally not have a scent, either, so if it smells unpleasant or generally off, then it's likely old. Finally, watch out for foam. When those impurities infiltrate the oil and you reheat it, they rise to the top in the form of unappealing frothy bubbles. The foamier your oil is, the older it is, but there is a caveat: there are a handful of other things that can cause foam, such as overheating the oil or frying foods from frozen, so on its own, it isn't always an indication that it's too old.

To properly dispose of the oil, let it cool, then pour it into a container with a lid and toss it in the regular trash. Use a non-recyclable container, such as a cardboard milk carton.

Once you've discarded the old oil, make sure any leftover crumbs or particles have also been removed. Give your fryer a deep clean at least once every three months to ensure no small amounts of old oil or long-term particles cause the new oil to go rancid.

If you don't change your oil, the most obvious result is that your food won't taste good. Leftover particles reduce the oil's quality, and will cause a burned, funky flavor as those leftover particles get fried over and over again. Plus, since the oil's smoke point reduces with continued use, it could pose a safety issue as overheated oil can lead to a kitchen fire. Consuming old oil can also potentially lead to ingestion of dangerous compounds that develop as the oil degrades, including trans fats and free radicals. While this won't necessarily cause food poisoning, it could cause other complications, including an increased risk of heart-related diseases.