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Oil 101

The recently started thread on this board about what oils a properly stocked kitchen should have frightened me. Smoke points, harmfully heated olive oil, finishing oils?! I don't know what these things mean!

Is there a good primer on cooking oils that someone can point me to? I use canola or olive oil for everything, including cooking in my cast iron pans which I gather is unsafe somehow? What does your average home cook need to know about the different oils out there?

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  1. Whew, I thought I was the only one.

    I use olive oil, vegetable/canola, and peanut oil depending on what we're cooking or frying. Hopefully someone will respond with some basic oil 101!

    1. Ok, let me throw something out. One of the many reasons people love olive oil is for its supposed health benefits due to its composition: like high in monounsaturated fats and low in unsaturated fats... etc. However, extra virgin olive oil has a very low smoke point. It starts to smoke at a low temperature. Oils quickly start to decompose around its smoke point. Therefore, just because extra virgin olive oil has a good healthy composition at room temperature, it does not mean it is healthy above its smoke point. I think some people overlook this and do not think rationally. Here are some quotes:

      "it is believed that fats that have gone past their smoke points contain a large quantity of free radicals which contibute to risk of cancer."


      "not only should olive oil only be stored for a few months after opening, but you should also avoid cooking food with Extra Virgin Olive Oil. This is because exposure to excess air, light or heat causes the fat to oxidize. When fat oxidizes, harmful substances called “free radicals” are produced that cause damage to our body’s cells."


      It is probably not as scary as stated above, but using extra virgin olive oil for high temperature cooking is not really logic from a health perspective. What is too high? Well, when it smokes.

      If you want to know more about oil smoke point, there are various lists on the internet. They are not exactly the same, but general thread is similar -- like extra virgin olive oil has a low smoke point. Needless to say, the smoke/fume from the overheated oils is not a good thing either. Refined oils always have high smoke points than their unrefined/cold pressed counter parts. This is because refined oils are more "pure". There are two lists for you to start:



      2 Replies
      1. re: Chemicalkinetics

        Thank you for the excellent reply! In the other thread a couple of people alluded to the dangers of using olive oil for high temperature cooking but didn't say why it is bad (probably because it's common knowledge?).

        1. re: NikkiTikkiTavi

          Your welcome. I should clarify that refined/light olive oil has a much higher smoke point. It is the extra virgin olive oil which has a low smoke point. In short, not ALL olive oils are bad for high temperature cooking. Just go by your real observation, when you see the oil starts to smoke, then you know you have exceeded its smoke point. Not good. Many people cook above the smoke point of extra virgin olive oil, but if you can cook below it, then it is probably fine. Trust your eyes. Best.

      2. One issue about oils is function in the kitchen, the other is a health issue. I wouldn't recommend you use this site to get answers about health issues, but you might get good leads on where to go for your own research about that (other than googling each oil).

        On the functional side, I don't worry about the smoke points. I typically use the grill outside for "charring" anything and a bit of olive oil on a steak works fine. I also stir fry, but I don't do it like in China...and I deep fry only a few times per year- so peanut oil works for me. Think about the way you cook. That is more important.

        As in most foods, I think the more natural, less processed, more cold pressed, unrefined- the better for most applications.

        1. There's always a new theory out there to scare us. Remember when margarine was good? Coconut oil was bad? Chocolate bad too? How about alcohol of any kind? Trying to keep up with all the theories on what is good for you and what is bad can be a full time job. I think the best thing to do is eat "real" food and sit down for a meal with others every day.

          1. Nikki,

            You're over thinking things.

            Use the K.I.S.S. principle.

            All you really need are probably 2 different oils, maybe three at the most.

            A good EVOO, which is good for basic sauteeing, cooking, and as a finishing oil (ie. on pastas or even as a salad dressing).

            Then you need to find a good oil for those times you want to deep fry. Peanut and corn oil are my preferred weapons of choice when it comes to deep frying. Both are tasteless and have high smoke points good for deep frying.

            There, that's all you really need in terms of oil in the pantry and as far as what to do with cooking oil.

            3 Replies
            1. re: ipsedixit

              I second ipsedixit, while I love olive oil it's not right for everything, a marinade, dressing, a brief saute, maybe the base of a slow sauce sure. otherwise canola or peanut IMHO. and maybe sometimes get all crazy with a splash of sesame for flavor.

              1. re: ipsedixit

                I never deep fry, assuming my understanding of the term is correct. Meaning submerging food completely in hot oil? I saute or stir fry often, usually in a cast iron pan. Would peanut or corn oil be more appropriate for those situations than EVOO? According to ChemicalKinetics' link upthread EVOO shouldn't be used for cooking. Or is that me worrying too much?

                1. re: NikkiTikkiTavi

                  You can saute and stir fry with EVOO. Most sauteeing and stir frying don't reach temps where the EVOO will start to smoke and the fats oxidize. So you're safe.

                  That said, I wouldn't stir fry with EVOO (at least for Chinese dishes) because of the strong flavor that EVOO imparts, better to use a neutral oil like corn or peanut.

                  Good luck and hope that helps.

                1. Since there have been so many helpful answers about cooking with oil, how about some tips on storing? I don't need to keep EVOO, canola or vegetable oil (the 3 that are in my pantry right now) in the fridge, do I?

                  ETA: I may have answered my own question by following EM23's link.

                  "Q: Where should I store oil in my kitchen?
                  A: Unfortunately, oils aren't like wine; they don't improve with age. Heat and light can damage oils, particularly polyunsaturated ones, so keep them in the refrigerator to avoid rancidity. For the record, you'll know your oil is rancid if it takes on a characteristic bad taste and smell, in which case you should toss it and buy fresh oil."

                  I have never stored EVOO in the fridge and have never had a problem with funny tasting or smelling oil. Do you? I'm not sure I have room in my little fridge for any more condiments!

                  13 Replies
                  1. re: NikkiTikkiTavi

                    Canola and most vegetable oil you bought are refined, so they have a relatively long storage time. Extra virgin olive oil... you just have to buy in small quantity and try to finish using it in 3-6 months. Of course, do not expose it to sunlight. You can store some of it in the refrigerator, which is what some suggests, but I think it is just easier to buy in smaller quantity.

                    1. re: Chemicalkinetics

                      Canola and most vegetable oil you bought are refined, so they have a relatively long storage time.
                      yes and no - it depends how long it's been sitting in a warehouse or on the store shelf. back when i used canola oil, i bought the occasional bottle that smelled off or indicative of rancidity from the moment i opened it.

                      1. re: Chemicalkinetics

                        CK: doesn't refrigeration just congeal it?

                        frankly nothing sits around too long in my kitchen...

                        1. re: hill food

                          Yeah, I don't know, but evidently many people refrigerate the oil.


                          You can also read the section of "TO REFRIGERATE
                          OR NOT TO REFRIGERATE" from Trade Joe's:


                          I don't think it is bad to refrigerate, but if possible, buying in smaller quantity is probably better.

                          1. re: Chemicalkinetics

                            jeez when I can I buy good but cheap olive oil in the 3L can and it only remains a few months and still tastes fine to the end (but then I use it whenever possible)

                            I still have an involuntary shiver thinking of the tiny bottle of Pompeii along with the dessicated herbs touched once in 8 years in a certain relatives place.

                            1. re: hill food


                              Are you a Spartan? I know you guys (Spartans) bath in olive oil before battles. :P

                              1. re: Chemicalkinetics

                                while I have driven by USC, I have never attended.

                                nah I just use it for any low heat purpose. (although sometimes butter is best)

                                1. re: hill food

                                  I buy it two liters at a time and certainly buy it two or three times a year. Doesn't sound excessive to me, hill food. It's by far my primary oil.

                                2. re: Chemicalkinetics

                                  It would take me years to use 3 liters of olive oil.

                                  1. re: Hank Hanover

                                    I may be exaggerating, I never keep a calendar on this, however one of the gallon(ish) sized cans lasts about a quarter of a year (eating in most every night) and works out cheaper on a per oz. basis. YMMV

                                    and it keeps my coat shiny

                            2. re: hill food

                              The big bottle of olive oil that I bought and stored in my basement pantry formed into a cloudy ball when it got too cold down there. I moved it to the (upstairs) kitchen and it seems to be fine after a day of being in room temperature.

                              I think I'll stick to keeping olive and canola oil in the cabinets and just be more aware of how much I'm buying at a time.

                              1. re: NikkiTikkiTavi

                                Nikki -- clouding is fine. I believe that storing at cooler temperatures is supposed to lower the rates of spoilage; if you store olive oil (and many oils) at a low temperature (50 and less) they will cloud and solidify, which is fine!

                                Hank... when I got good deals on olive oil I was using a 5L jug about every 6 months. Which is about 3 tablespoons a day, which is what... 380 or so calories... if my math is correct. That's not really that much.

                                1. re: mateo21

                                  Trust me... calories are not my concern. I love a good evoo. I just don't use all that much. I don't saute in it. Oh, sometimes I do with a little soybean oil to lift the smoke point. I hate vinaigrette salad dressing. I like to dip bread in it.

                                  What can I say.

                        2. Cook's Illustrated has an article named cooking oils 101, I think. http://www.cooksillustrated.com/howto...

                          Here are a few links to oil smoke point lists.




                          Bottom line. The thing you need to know is the more refining the oil experiences (refining usually means filtering), the higher the smoke point, the clearer the oil is and the less flavor it has and less it is subject to going rancid.

                          Clarified butter actually has a pretty high smoke point because the water and the milk fats have been removed.

                          Most nut oils like walnut or hazelnut is not refined, they are being used for the flavor in things like a salad dressing. Peanut oil is one of those wonder oils. if it isn't processed, it tastes like peanuts and has a low smoke point. If it is heavily processed, it is clear, almost tasteless and has one of the highest smoke points around.

                          There are a few oils that make chowhounders go berserk. Tell them that you own stock in a canola oil factory. They will go nuts. Don't ask me. Apparently there is some health concerns that aren't shared by the Food and Drug Administration. Never mind that half the chefs on TV use it. I'm sure you will hear all about it.

                          Flavored oils need refrigeration. Take them out and let them warm up before you use them. keep them in the dark and well away from the stove or the oven.

                          An absolutely perfect place to store oils is a wine refrigerator. They chill at about 55-60 degrees F and they usually have darkened glass doors.

                          That's all I got... hopefully, it was helpful.

                          14 Replies
                          1. re: Hank Hanover

                            "Tell them that you own stock in a canola oil factory. They will go nuts."

                            Really? I have not encountered anything like that. Sound like you have stock in a Canola oil factory and was shouted down, huh? :) I must have missed that fight.

                            1. re: Chemicalkinetics

                              I don't own a lot of stock of anything but there were a few very animated discussions in the past.

                              Quite frankly, I can't remember whether I got involved or not.

                              Here are a couple of links to chowhound threads that got heated.

                              http://chowhound.chow.com/topics/494638 2/29/2008

                              http://chowhound.chow.com/topics/705676 5/3/2010

                              But other than that one teensy little controversial comment, I think my post was fairly informative and while I clearly indicated what side I was on, I did indicate that some had health concerns and I think it was fair to say that those concerns were apparently not shared by the FDA.

                              Nope, I didn't get involved in either thread because I didn't have a pony in that race. I had to go check.

                              1. re: Hank Hanover

                                Yes, some of the exchanged got pretty animated for sure. :)

                                1. re: Hank Hanover

                                  good point about clarified butter (ghee) it sounds wrong but does have a very high smoke point.

                                  1. re: hill food

                                    Yeah, I had some clarified butter (ghee). It wasn't cheap, but it tastes wonderful. Maybe mine wasn't extremely purified, because it still smoked at a temperature lower than those of refined corn oil or refined peanut oil. However, my ghee definitely smoked at a higher temperature than regular butter.

                                    I think a lot of people like to cook in butter but find it limiting due to its smoke point. Clarified butter/ghee would be a good alternative.

                                    1. re: Chemicalkinetics

                                      Whe cooking with ghee,use a mix of ghee and oil ( any kind that you use), that way you get a higher smoke temp but the flavour of ghee is there and you dont end up with burnt ghee smell. And ghee unlike other fats will keep the heat even when taken off the flame, so being alert and quick is key to working with it.

                                      1. re: shakkar

                                        "Whe cooking with ghee,use a mix of ghee and oil "

                                        :) Same trick people use for butter. Thanks for the advice. I will just have to wait for a price reduction for my ghee.

                                        1. re: Chemicalkinetics

                                          I just make my own clarified butter in the microwave....made some yesterday for French toast. Is ghee you buy better than homemade?

                                          1. re: escondido123

                                            I am glad you asked that question- because I too make mine in a few minutes from organic butter. Easy peasy. Why buy it?

                                            1. re: sedimental

                                              Here is a link to the epicurean food dictionary on the subject: http://www.epicurious.com/tools/foodd...

                                              It is my understanding that ghee has been simmered until the milk solids browned giving the butter a caramelized flavor. It usually has even less water than most clarified butters and has a slightly higher smoke point enabling sauteing. At least at one time was made with water buffalo butter.

                                              It seems very expensive to me in the stores.

                                              1. re: Hank Hanover

                                                So the two terms are not synonymous--thanks for the heads up.

                                              2. re: sedimental

                                                Because, where I am, ghee is cheaper than butter. Go figure.

                                2. re: Hank Hanover

                                  The cooks illustrated link looks to be very informative, thank you!

                                  Other than price, how do I know how refined an oil like peanut is? Will it be obvious when I look at the bottle?

                                  1. re: NikkiTikkiTavi

                                    The label will say refined and the oil will be so clear that it will be undeniable.

                                    Some labels will say semi-refined. Those don't have the level of refinement required to have a high smoke point.

                                    After I researched it, I ended up usually using Crisco vegetable oil which is soybean oil. Fills most of my needs. Higher smoke point than canola, tasteless and recommended by Cook's Illustrated. It isn't ridiculously priced either. I use peanut oil for deep fat frying.

                                3. Nut oils and sesame oil spoil easily and should be refrigerated or even frozen. Put the bottle on the counter a few hours before you want to use it. Any other oils that are infrequently used should be bought in small amounts, and if there's room to refrigerate, do so.

                                  You don't NEED a variety of oils. A high smoke point oil like peanut or corn can serve all food prep purposes. Americans over 50 or 60 grew up in an era when supermarkets sold vegetable/corn oil, and MAYBE one or two styles of olive oil. Our mothers wouldn't have known what to do if faced with the array of choices in modern supermarkets, much less ethnic markets. Oils used for flavor and garniture - olive, nut, truffle.... - can be thought of as seasonings rather than essential kitchen staples.

                                  1 Reply
                                  1. re: greygarious

                                    Sometime "choices" are confusing if not bad. The USSR got it correct when they offer just one brand -- government brand (my friend who lived through USSR told me that they didn't have 50 different brands of the same thing.)

                                  2. As you requested overview information here are some links with information on oil of all kinds:




                                    Some oils need special handling - even with that some go bad way faster than others. When oil goes bad it or anything you made with it will taste very ransid and discusting. So I make it a point to have only a little around and keep it rotating through to be fresh.

                                    Smoke points sorted by temp and sorted by name:

                                    One organic supplier of different oils with prices (can click on the left to see the food label specs for each kind they sell):

                                    Here is a link to the USDA database for food labels as well:

                                    There are all kinds of opinions on healthy cooking oils and storage like:

                                    We all cook different. Think about how you cook. For me, I usually fry on smoking hot heat or sauté. There usually not very much oil in my house.

                                    If it is going to be smoking hot I usually use bacon fat on cast iron like my grandmother who lived to be 97 did. (and her mom also lived to be 93). Yes I said saturated fat in moderation. It adds great flavor and can be cooked in very hot. This works good to cook a salted steak in a couple minutes on each side with a nice crust while medium rare in the middle (I have to take smoke detectors if do inside, so cook my steaks outside now on an extremely hot fire in the pan for the best crust or without as BBQ is always good and uses no added oil).

                                    If hot but not quite that smoking hot I use a little peanut / corn / canola / vegetable oil and try to cook with it below its smoke point. Peanut is what I use most here as comes off my cast iron better than the dark colored sticky residue canola / vegetable oil leaves that is hard to scrub off. Find do not cook very much in this middle high temp range and at this time do not have any of those oils in the house. This is how I do potatoes to get them golden on the outside and soft on the inside while don't eat fried foods very often as seems to help my waistline go down.

                                    Sometimes I use coconut oil because of supposed health benefits as is said to increase metabolism to help me loose weight and have more energy. Have been trying to eat more of it when love olive oil usually for these applications. Find coconut sometimes adds unique nice subtle taste depending on what I'm making. It doesn't get soft until 76 degrees so I sauté with it in non-high heat situations as is usually hard until heated:

                                    Extra Virgin Olive Oil can be used without heat or further processing unlike many of the other oils. Mechanically cold pressed is best while hard to tell from lables. As is straight from nature is better than eating something that has been heated or processed. EVOO is what I like to use for flavor and on salads. Gets hard in the fridge so I make my Italian without oil and sometimes eat it that way. If oil is added try to add as little as possible right at the table. Balsamic vinegar drizzled with the olive oil and my Italian mixture is a favorite on salads and for dipping my sandwiches made without mayo. Right now I'm eating Santini the stuff in the green bottle with the poor spout at TJs $7.99 for 32oz and plan to next try the TJ Greek Kalamata olive oil. I buy my oil in glass not plastic because of concern tolulene and other chemicals can leach into food that contacts plastic (especially new plastic in contact with oily foods - a well used plastic water bottle is better to drink from than a new one). I keep my olive oil in a cold dark cabinet as light can make oil go bad faster. Here is some general olive oil information.

                                    There are many good olive oil threads here on CH with this being just one of them:

                                    Have been making thick sauces, dips, spreads, and dressing with a combination of fresh squeezed lemon juice with blended beans / powdered nuts or combinations of both. My favorite bean for this is garbanzo and my favorite nut is almonds. Fresh almonds get blended into a fine powder to work as a thickener - some places sell almond flour for smother sauces. Blended beans will also thicken most anything. We make great tasting thick no oil nearly neutral citrus / bean / nut sauces that can be flavored - curry or chipotle are our current favorite variations. This has helped me eat lots less Hellman's / Best Foods / Unilever mayo (which is mostly oil).

                                    1. I use corn oil as my compromise oil. Not much to add to what others have said, but point out that you really want different oils for different purposes. Many over state health claims, and a CK has pointed out, the oils can change depending on what you do with them.

                                      Olive oil is best for flavor, non-cooked.

                                      And, you need to watch for the total amount of fat you use as much as what kind.