The Incredibly Simple Way To Elevate A New Batch Of Frying Oil

Anyone who's ever tried deep-frying at home knows the deal: The first few items you dunk in there will always turn out paler and less crispy. It takes a few rounds for your oil to start churning out consistently golden-brown results. And while a few soggy fries isn't the end of the world in the grand scheme of things, losing ingredients to just the warm-up can get frustrating. Thankfully, there's an incredibly simple way to jump-start your frying efforts: Add some used frying oil to the mix.

The idea that adding degraded oil helps a fresh batch taste better is slightly counterintuitive, but there's a good bit of science behind it. When oil undergoes a heat cycle, it extracts moisture and particles from food and begins to break down and lose some of its hydrophobic qualities — or resistance to water. A slightly adulterated oil responds more effectively to a food's natural moisture, which gives you a more even fry from the get-go.

While you are always free to eyeball things, adding until the new oil acquires a bit more color, America's Test Kitchen found that a ratio of 4:1, fresh to used oil, worked best. The rub when doing this is that improper recycling, storage, and disposal of oil are some of the most common mistakes people make when frying food, and you don't want to spoil a fresh bottle. Using oil that is too degraded will result in food that is unappetizing at best and dangerous at worst. 

The tricky part is that it can be challenging to know precisely how many heat cycles a batch can withstand — it's all to do with what you're frying and how well it's strained when reusing. A good rule of thumb is to limit the reuse of any one batch to two or three times. It will help with the overall quality and longevity of your used oil to strain it with a fine mesh filter or cheesecloth after use and store it in an airtight container. Also, remember that some foods will ruin oil faster than others — fatty meats and overly floury batters are the worst offenders. When in doubt, play it safe and start over with fresh oil. After all, a few ruined warm-up pieces is better than ruining the entire batch with spent or expired oil.