9 Uses for Rancid Cooking Oil

Now, I won’t say that I am cheap, but I never like to see waste. I use everything that I can. As many of you know, the shelf life of cooking oils is not indefinite, so the other day I found some olive oil that was out of date. I got to thinking about alternate uses for rancid cooking oils. Here is the list of uses for old oil.

Lubricant and rust preventative.  It can be used for everything from squeaky hinges to oiling your tools. In a pinch, it would work to protect your firearms.

Lamp oil.  Oil lamps are a good alternate use for rancid oils. They are easy to make and put out about the same amount of light as a candle. Having a selection of oil lamps is a very good prep and lamp oil, like this brand, isn’t too expensive.

Furniture Conditioner and Polishing Agent.  Cooking oils can makes a great wood furniture polish and conditioner. I have used it on butcher block in the past. Combine equal parts oil with vinegar for an amazing mixture that can make old, scratched furniture look almost new.

Olive oil softens and preserves leather.  You can also use it on leather to help restore suppleness, and protect the leather.

Get paint off your hands. Rub some oil into your skin, let it sink in for 5 minutes, and then wash thoroughly with soap.

Protect rattan and wicker furniture. It helps keep rattan and wicker furniture from cracking. Just gently rub some warm oil into the furniture with a soft cloth.

Making soap.  Rancid oils can be used to make lye soaps. This book is a classic for basic soapmaking information and instructions. This would be a good skill to have for TEOTWAWKI.

See also  What Is A Ceramic Pot Heater And How To Make Your Own

Animal feed.  Dogs and cats do not appear to be bothered by rancid oils. Add a little to their food and it will improve their coats.

Making Diesel.  Old cooking oils can be processed and burned in diesel engines.

These are the alternate uses for rancid cooking oil that I came up with after a few minutes of thought. I am sure there are many more. Every now and then, somebody I know wants to get rid of old cooking oils. I tell them to mark it as not fit for human consumption and keep it. It may come in handy someday.

If you’re wondering why it’s not a good idea to eat rancid oil, read this.

Try to find multiple uses for everything you store.


A Must Read
We earn a commission if you click this link and make a purchase at no additional cost to you.

29 thoughts on “9 Uses for Rancid Cooking Oil”


  2. when I owned a tree service, I was always getting pine sap on my hands and in my hair. rather than using a solvent, I would use cooking oil on the pine sap, let it soak then wash my hair or hands with soap as usual. this was on the coast of n. ca. it may not work on high elevation pines. the pitch of pines at 7000′ in the sierras wasn’t nearly as flammable as the pines in coastal california

    1. I use it to remove pine sap from my hands too… and the hood of my car, as we have pines over our driveway. It is also a good first step to clean hands after getting greasy working on car, lawnmower, etc… step 1: Wash hands with cooking oil (no soap or water) 2: remove excess with paper towel, rag, or dirt, sand from ground. 3: Wash with generous amount of dish soap, just a sprinkle of water and either sand, dirt, or coffee grounds (better than pumice as a “scrubber”)

  3. Olive oil and peanut oil can be used to soften and preserve leather. Corn oil, canola oil, and linseed oil should never be used on leather. They will dry hard and make the leather brittle. They do make a good sealant or paint base for use on wood, especially if thinned with a little turpentine. Olive oil, alone or mixed with glycerin, is an excellent skin conditioner. Most oils mixed with borax make a very effective rat poison. Oil on stale bread can be used to bait live traps.

  4. For those who cast theur own bullets and reload their own ammunition, particularly for antique black powder cartridge rifles and revolvers, a 1:3 mixture of vegetable oil and beeswax is a traditional ratio used for patch and bullet lubricant, as well as gun grease for black powder revolvers, going back to the Mexican War.

  5. You should never use vegetable oil on butchers block, cutting boards, counters, etc; especially racid oil. Rancid means it’s decomposing, ie “rotting”. And I’m not sure I would want to use rancid oil on leather I wore or used in hand.

  6. Your link for the soapmaking book is invalid.
    Next time, include the title so even if the link goes bad the reader can search for it.

  7. Other uses:
    Mix with sand and stick your gardening tools such as trowels in the sand to keep them rust free.
    Oil works great to remove other oils and sticky things from skin, surfaces, etc. I just wouldn’t use rancid oil on my skin.

    Pets should not eat rancid oils either.
    Rancid oils should not be used on our skin or anything that touches our skin.

  8. We use vegetable oil for bar oil in the chainsaw. Rancid might work just fine. Bar oil tends to spray all over the place so now we have less fossil fuel on our land.

    1. I haven’t thought of that, but I don’t think it would be a good idea. When oil becomes oxidized, it becomes rancid, and the process produces free radicals, which are bad for the human body, both inside and out.

  9. Well, there are two concerns with *rancid* oils:

    1) They are decomposing, and thus should not be consumed, possibly not by pets, either, and should not be used on cutting boards, either; and
    2) They STINK!

    Now, I read on a soapmaking blog that you could use rancid oils to make 100% saponified soaps and simply add some pleasant scent to the soaps. I gotta wonder about this.

    Would the rancid smell still potentially be an issue that may just be being masked? I know that I would worry about this with any type of polishing or shining I’d otherwise consider — and with the oil lamps as well, to be honest.

    Might rancid oil soaps possibly not be the best choice for hand washing, due to possible pathogens from the “rancid” factor, or are all potential pathogens killed by the soapmaking process? I don’t know.

    I also wonder how the fat / oil content in homemade soaps compare to store-bought: is one easier on wastewater pipes than the other? For example, does one contain more grease that might cause clogging when used long-term, or is the grease / oil in the soaps not a major issue in general? I don’t make soaps and am not a chemist / biochemist / microbiologist, so I don’t know.

    Just a few thoughts. I think it’s a great idea to brainstorm ways to reuse anything we can, so thanks! Even if not every way might necessaily work, it can at least get folks discussing the issue, which could help us find viable solutions in the end. =)

  10. Oh yeah, almost forgot: I believe that rancid oils also aren’t the best for biodiesel, either, due to the fact that the oils are already decomposing. Unless I’m mistaken, if the oil would be a safe and healthy oil for you to cook with — i.e., fresh and vegetable-based — then it’s probably a good candidate oil for biodiesel. But, I would check with actual biodiesel researchers, in case I’m wrong.

    Trust me, I wish I knew how to compost the stuff. Could it be anaerobically composted? I actually don’t know. I would worry about the water repulsion issue in the soil. Sorry, wish I had better answers for you all. But if you got a solution that works, please speak up! =)

  11. I think whoever wrote this article should never give advice to anyone for anything. They obviously do not know what they are talking about.

  12. So, if oil can be used to remove paint from hands, could it be used to soften and remove old dried paint drops from a finished wood floor? I’m reluctant to try paint thinner or turpentine because I think it’ll remove the floor finish too (I rent so that would not be appreciated by my landlord… although why leaving them there for the tenant to live with… but I digress).

    1. Yeah, rancid oil forms free radicals which are very unhealthy. It also smells and tastes bad. Years ago when I lived near the Navajo reservation, my co-workers would give me homemade fry bread, and often, it had been cooked in rancid oil. Not good at all — in fact, I can still almost smell it after all these years!

  13. Please remove the “animal feed” suggestion. Feed rancid oil to your animals is NOT healthy! Rancid oil can cause organ damage in both humans and animals (and many humans can’t taste the rancidity either).

  14. Barrett Hoines

    I use old oil for knife and other blade sharpening, drilling metal and general lubrication, but not on my wood cutting boards. It’s also good for bicycle chain oil (less petro on the land). I don’t give it to animals, or put on leather because of the smell.

  15. Soaking stinking rancid oil into your wood furniture and leather clothes is a very bad idea unless you’re looking for an excuse to throw out your wood furniture and leather clothes.

  16. Please don’t give rancid oil to dogs cats or any animals to eat, it is damaging to their heart and health …it should not be fed to pets for the same reasons people should not eat rancid oil.

    The rancid oil will damage your pet’s health in the long run !!

    1. Thank you for that, Sacha. All dry pet food that I know of contains oils, and it does become rancid. I do not know, however, from a veterinarians’ perspective, how damaging that is to their health.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top