Re-using deep-frying oil

I made doughnuts for the first time a few weeks ago, and I must admit, I've been craving them ever since.

Two things have been stopping me: (1) they're not that good for you, and (2) they're expensive because it takes a lot of oil to deep fry them.

I threw away my frying oil last time, but I've been wondering if it's okay to re-use. I did a bit of reading today, and it looks like the answer is yes. Yes, it's okay to re-use your frying oil.

Here are three helpful articles/conversations that I read:

Here's my plan for possibly re-using my oil next time I deep fry something:
  • Keep using canola oil.
  • Use a narrower pot and fry fewer pieces at a time so it uses less oil.
  • Try to keep the oil from heating up over 375° (I actually had a hard time with that when I made my doughnuts earlier this month).
  •  Filter and store the oil (possibly in the fridge or freezer) after it cools off.

Hmm . . . I just realized that since my oven is broken, I need to make doughnuts today so we have something to go with our soup for dinner. I guess we'll all just have to suffer through them.


Do you re-use your oil? Do you have any tips? How do you store it?


  1. Diana, yummy.. love doughnuts..
    I do save my deep frying oil.. [for several uses].
    I let it cool, strain it and put it in the deep freeze..
    The next time you use it, you need to take it out early,
    because even though, it is oil, it will be in a semi-frozen
    state and needs to thaw some.

  2. I've read lots of the opposite - that seed and grain based oils, like canola (soy bean oil), are unstable at higher temps - like those used for deep frying. They oxidize quickly and cause oxidative stress (inflammation) in your body as a result. Not only should you not REUSE already damaged fats to deep fry again, but you should not use them for the purpose of deep frying - ever! That said - I think tallow or lard MAY be reusable, as they are more stable to begin with (and better for frying). Just clean the oil through a strainer and/or cheese cloth and then refrigerate between uses.

    I've not done this myself - but I do use a mix of butter and bacon grease when I pan fry things at home.

  3. (I would add that my mom used to reuse our frying oil growing up - and I did notice that it started to have a noticeably different almost rancid flavor if used for more than two batches of frying).

  4. I've reused canola oil before. I didn't even refrigerate, just strained and saved in a jar in the cupboard. I do toss it after a while if it doesn't get used.

  5. I do reuse oil from deep frying. I start with peanut oil as it will take the heat of deep frying without oxidizing. I keep two food-grade plastic jugs (from vinegar) and I strain the oil into the appropriate jug. I keep one for sweet deep-frieds (such as donuts) and one for savory (such as battered fish). We don't deep fry often but I find I can keep these sealed and stored in my cool cellar for several months. Peanut oil is expensive but worth it, I believe, for health reasons. If you can purchase the large container from, say Sam's or Costco, it will also keep for many months in a cool, dark place and be a significant savings over smaller containers from the grocery store.

  6. Thanks I have always saved my frying oil but never really knew if I should or not.