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Rancid (slightly) oil -- still usable?

I have a large bottle of canola oil that just turned rancid. I'm wondering if it's actually bad for your health to consume rancid oil, or is it only a bad smell without ill health effects? Just thought maybe I could deep fry something with all that oil instead of just pitching it all.

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  1. Pitch it. Just pitch it. There's nothing like something cooked in or with rancid oil - even just a teensy bit rancid - to put you off your kibble forever. Seriously. I don't think it's dangerous, just horrible.

    3 Replies
    1. re: Nyleve

      I agree - just pitch - I think the deep fried food would taste like rancid oil - I once used oil that I only smelled after the dish tasted funny, and rancid canola oil was the culprit.

      1. re: Nyleve

        Do NOT eat that oil, in any shape or form. It is extremely bad for you, causing tumor-suppressing genes to turn off and increasing your chances and potential liver damage. Vegetable oils are unstable to begin with, processed using hexane and high heat, and should be avoided for high-heat cooking. The healthiest fats to use are high in saturated fats, like butter, ghee, coconut oil, and lard.

        1. re: Nyleve

          OMG WHY would you even want to? or even consider it? Out it goes.

        2. Cooking food in rancid oil is like throwing good money after bad. While I'm sure it won't hurt you, anything you cook in it will taste off and you will end up throwing it away. Better to save your good food and throw the bad oil away!

          1. I agree.. Especially when you can get a nice new bottle for $3 at Trader Joes...


            1. Lol! Was not trying to be cheap--really! And everyone is saying what I knew i should do, so I'm pitching it!
              Thanks all.

              1 Reply
              1. re: slacker

                Ya, at the price you pay for canola oil, it's a no brainer.


              2. Unless you know someone who makes biodiesel.

                1 Reply
                1. Hmm, this post made me realize I think my jug of canola oil from Costco might have turned a wee bit rancid (though it's only a few months old). I started tasting the "rancid" taste on the outside of my quesadilla last week but hubby said that's what canola oil tastes like. Yeah honey but I didn't taste it before. Could it be rancid, or did I just never realize canola oil tastes bad? I don't taste that taste in the hi fiber choc chip cookies hubby makes every week.

                  6 Replies
                  1. re: Alice Patis

                    The flavor probably comes out more in a lightly fried item with few ingredients (quesadilla) than in something with tons of sugar and other flavors (cookies). Toss it!

                    1. re: Alice Patis

                      I suspect that your hubby may be partly right. I personally don't like canola oil because, despite what everyone else says about it, I don't find it flavourless at all. It always has a bit of a heavy off-taste to me. I prefer sunflower for everyday use, when I'm not using olive. But when it goes rancid it's really ucky.

                      1. re: Nyleve

                        There was a good post about a week ago in the General topics board about Canola tasting funny to some people. I agree, I think it usually tastes rancid and smells funny. I have switched to Grapeseed, safflower, soya, and peanut for uses that olive isn't right for.

                        1. re: Atahualpa

                          Canola definitely has a fishy smell to me. I've stopped using it.

                          I actually pretty much completely stopped using vegetable oils (Other than sesame and evoo) and do all my cooking with animal fats now.

                      2. re: Alice Patis

                        Based on what I am reading in this thread, is it possible that Canola Oil turns faster than other oils? I am not a fan of it, wary of it, believe its origins are from genetically altered plants. Am I wrong?
                        I prefer corn oil, sunflower oil to canola oil. As well who promotes it and what incentives are there for this vast promotion that we see on TV?

                        1. re: Ruthie789

                          like all other plant-based oils, some it comes from GMO, some of it doesn't.

                          Northern Europe, which is pretty militantly non-GMO, is covered with blankets of eye-popping yellow flowers in the spring....it's colza - the French word for canola. Europeans cook with it all the time.

                      3. THROW IT OUT.
                        GET FRESH OIL, WHATEVER KIND.

                        1. Rancid oil has bad stuff in it. And even before it goes rancid, canola oil is pretty highly processed.


                          1. Here is a website that has a list of things to do to make rancid oil sweet. I found it to be quite interesting. I haven't tried any of it and have thrown out my share of oils from the yearly Thanksgiving turkey fry!


                            I have NO IDEA when this book was written.

                            1 Reply
                            1. re: wholeheartedbaking

                              1857. I'd be suspicious.

                              Even though I have a LOVELY quart of duck fat that is just starting to smell a teeny bit off. I threw it in the freezer, but am thinking I should just pitch it. What a waste. I'd love to find a way to redeem it.

                            2. Rancid fats are among the culprits in liver damage and increased LDL (bad) cholesterol levels. Whatever it is, if it smells rancid, don't consume it.

                              1. I'm using a bottle of olive oil that has turned rancid as a household lubricant on items like my Champion juicer. Be sure to write on the bottle, so someone doesn't mistake it for cooking oil. I keep mine under the sink. (This olive oil was an experiment, a brand I never bought before, and won't ever again, as what I usually buy doesn't go bad so quickly.)

                                1. Use it for shoe polish, nothing else.

                                  1. Here's a good way to use up rancid oil. Check out "Homemade Vegetable Oil Lamp":


                                    1. We've been buying canola for years from Costco, but the past two jugs we purchased smell bad. They are not old, we just bought them, and the expiration date is 10 months in the future. Before these the canola just had a neutral type oil smell. This is a new problem for us, but other people say their canola oil has always smelled bad.

                                      1 Reply
                                      1. re: nblisa

                                        I think canola oil smells fishy and I've stopped using it.

                                      2. Rancid oil is just bad for you. I've heard that canola is not good in general?!?!

                                        1. Chuck it and don't bother buying canola oil again. It's rancid from the start... they have to make it that way to make it "shelf stable" and then they process it to remove the smell/taste so you can't tell the difference.

                                          Rancid oil is toxic.

                                          If you're looking to fry something, try coconut oil. It's healthier for you and the best one to withstand higher cooking temperatures.

                                          3 Replies
                                          1. re: cturner22

                                            Not really. Coconut oil is healthy, but it doesn't withstand higher cooking temperatures. It's smoke point is 350 F (177 C). I'd use extra-light olive oil - smoke point is 468 F (242 C) and it is the lowest in polyunsaturated fats, which are highly prone to oxidation (become rancid). It's mainly monounsaturated fats that are more difficult and they take longer to oxidize during storing and termic preparation.

                                            1. re: cturner22

                                              Well the Internet contains lots of "information". Not that I don't believe people here, but can someone provide some concrete evidence that Canola Oil is bad in general? Here is something I found on snoped: http://www.snopes.com/medical/toxins/...

                                              Some people still think MSG is toxic - it isn't.

                                              1. re: cturner22

                                                Better peanut oil for deep frying. Be warned that stuff fried in coconut oil and kept for too long, like snack stuff, will go rancid. At least in a hot climate like I have,

                                              2. Use for rancid oil:

                                                Midwinter herbicide for spraying fruit trees, etc. to kill overwintering pest eggs.

                                                Strain, use a detergent like Dawn to make it spray better.

                                                1. Toss it. Many years ago I had a bottle of reallty good olive oil that I continued to use when it 1st started to go. I was told by an oil purveyor that you can actually get food poisoning from rancid oil. Toss it.

                                                  1. Another use is to use it to flush out the bar oil system on your chain saw before using it with good vegetable oil to split and cut up moose, elk or the family beef cow. It takes a couple of loads of eatable oil through the system to get rid of the regular bar oil.

                                                    1. I just put and ate grapeseed oil in my salad and now i am not sure if it was rancid. & i looked up what it can do, Botchellism, cancer, DNA damage etc and now i am freakin out. Would one time cause these things?

                                                      2 Replies
                                                      1. re: MimiP

                                                        If it did not taste bad it wasn't rancid. Even if it was I doubt if one salad is going to damage your DNA.
                                                        Try to enjoy life more.

                                                        1. re: MimiP

                                                          Who knows what amount is dangerous? For sure, though, in the modern world we are exposed to toxins and mutagens on a regular basis, through many things that we consume, inhale, and touch. Use common sense but it's useless to obsess about it. Stress might be more dangerous than actual toxins.

                                                        2. Reminds me of college chemistry class where somebody spilled a bottle of butyric acid and the lab stank of rotten butter the whole rest of the semester. Toss it.

                                                          1. It's rancid! What is wrong with you, it has to taste like crap. Throw it out.

                                                            Are you someone who craves buffalo wings? (((Shudder)))

                                                            3 Replies
                                                            1. re: law_doc89

                                                              +1 for the relevant portion of your comment.

                                                              Please, don't pepper your replies with hostility towards Chow or Hounds.

                                                                1. re: Brandon Nelson

                                                                  Ha I just realized that. At this point, I'd definitely not use it.

                                                              1. I know a very Highly acclaimed Natural doctor and he says not to use oils to cook with of any kind, not even extra virgin olive oil or even coconut oil, he said there is no way to tell if it has been exposed to air in the process of manufacturing it and he said there is no way to tell how long its been sitting on the shelf, he said if its exposed to air it can become carcinogenic, and can cause cancer and that is the reason why one really well known guy died from Cancer because he ate alot of stir fry and cooked it in extra virgin olive oil at high temperatures, he said you are much better off cooking all of your food in butter, and cook at a low heat, as far as stir fry goes you can add water to the pan and cook it in water alone or add a little butter to the water. I would not reccomend using any oils for cooking and especially not Canola oil - its got alot of bad stuff in it, you can look it up on Youtube. Since I quit using Extra Virgin Olive Oil for cooking, I have found many other great uses for it, I use it for Furniture Oil, just Straight Extra Virgin Olive Oil, and am loving it far better than the yucky petroleum based furniture oils in the cleaning Isle, It also gets sticky residue from price tags off very easily - so I don't have to buy the chemical laden sticky removers at the store and have chemicals get in the water system. I use it for shaving my legs and it also moisturizes at the same time. I mix it with some sugar in a glass container with lid for a hand scrub - that gets the dead skin off your hands and moisturizes, and store the remainder in the fridge to use again. You can use it as your night moistuizer on your face, would probably make your makeup slide off if you wore it for day. Right now I am trying to use up some canola oil that somebody gave me, but I would never use it in my food or on my body so I've been using it for furniture oil, and it works perfectly fine, when I run out I will switch to Oliver Oil, I'm guessing you could use Rancid oil for Furniture oil, as long as the rancid smell doesn't stick around. Another thing I heard about Canola Oil is that it's used as a Pesticide, and when it's in your body it acts like a glue, and is hard to get out of your body. I too thought Extra Virgin Olive Oil was healthy to cook with for alot of years, but now I will only use Unsalted Butter sticks , and don't buy the butter that comes in the plastic tubs or margarine, they usually have canola oil in them or a bunch of other bad ingredients. Also do not buy the majority of Salad Dressings, most of them have canola oil or Soybean oil in them, both are bad, find a healthy salad dressing that does not contain either of these, you will most likely have to go back to the health section, but even in the health section you will still find these ingredients in the dressing, so read your labels. Best way to avoid these oils is to make your own healthy salad dressing. You could just squeeze a lemon slice on your salad, or one I like is Lemon Juice, Lime juice, Apple Cider Vinegar, and salt & Pepper, just play around with it to get it to suit your taste buds. And Remember don't cook with oils, just cook with Unsalted butter cubes.

                                                                6 Replies
                                                                1. re: triscuit1

                                                                  What exactly is a "natural" doctor? Are you talking about someone with a medical degree or PhD? Sounds like a quack to me.

                                                                  1. re: phofiend

                                                                    Usually - natural doctor is someone who tells you what your MDs and PhDs will not tell you about food, therapies and lifestyle habits pertaining to health.

                                                                    Doctors often cannot volunteer the information on foods, remedies and therapies, even on those with which they may agree - they toe the line. Legally they can only agree to certain subjects if you as the patient broach them.

                                                                    This situation doesn't make bad natural doctors any less dangerous to you and I, but it doesn't guarantee the safety of the more well-lettered practitioner either.

                                                                  2. re: triscuit1

                                                                    Canola oil is not dangerous and is healthier for you than most oils. The statements above are scientifically unsound.

                                                                    1. re: calumin

                                                                      Canola oil is an engineered, heavily processed product, it is not a simple plant-derived oil like a traditionally pressed product that has a real plant name in from of the word 'oil.'

                                                                      I expect people to make their own call based on this, not accept what the Canola marketing team (or Health Canada's scientists) tells us looks good on paper.

                                                                      1. re: JonasOftoronto

                                                                        yes, that's why Europe produces and consumes thousands of gallons of the stuff every year (and has been before anybody even knew what GMO meant)....compare the GMO stance of Europe to North America.

                                                                    2. re: triscuit1

                                                                      I wasn't aware there were studies suggesting cooking with oil is carcinogenic--who is the doctor you reference? I'd like to read his studies for myself. Thanks :)

                                                                      1. Best plan - learn to detect any trace of rancidity ie. bitter unpleasant smell and taste in many foods - and reject.

                                                                        This has to be learned, whether it's in cooking oils, the flour in your kitchen, the corn chips and crackers you buy, or the takeout you go to every week. Notice the smell. Carefully taste. Damaging free-radical oil rancidity is so widespread in our commercial food supply we've just gotten used to it, while those in the industry have gotten rich from using these cheap, poor-quality ingredients.

                                                                        By contrast fresh natural foods do not have rancidity, they are 'clean' so to speak - are usually sweet and pure with no off-tastes. So there you have your basis of comparison to 're-learn' what is clearly bad for you.

                                                                        1. Do not use it. Rancid oil will make you all sorts of ill.