SMOKE POINTS of Cooking Oil: A general summary about seasoning:

 

Cast Iron Skillet

Why seasoning your Cast Iron?  It protects the finish surface from oxidizing as bare metal will rust.  Some cast iron sold new that is gray in color has been given a wax coating to prevent oxidization, but the wax must be removed before seasoning.  The purpose of seasoning also provides a slick surface that prevents food from sticking to the cookware.   
 
What is seasoning?  It is a black finish to cast iron which helps prevent oxidation while also giving the item a non stick surface. s the cast iron once clean is covered in a light coat of oil, the cast iron is heated.  

How does this work? As oil bakes past the smoke points, it leaves a black patina finish, (carbon).  This carbon is polymerize as the oil is seared onto the cookware through the process of heating at a high temperature.  Once the oil has burned away, it will leave this finish known as seasoning.  Many manufactures preseason cookware but in time, reseasoning may be required. Once the oil has been heated, it is cooked into the surface of the item and when cooled, the first level of patina finish remains and once cooled will have a smooth touch.  Over time, through use, more oils are added while cooking and when kept properly, only gets better through time. 

What oils work best?  Cooking oils whether vegetable or animal fat both work.  I have used different oils over time seasoning many different types of cast iron cookware with great results, but only oils at or above 350 degrees (f) seem to work best.  I like bacon grease, although vegetable oils work fine and as I often cook using olive oil,  it too, works great.   What you use, truly is up to what you like and use in your home. What perhaps is more important in selecting what oil you use, is deciding which not to choose.  Since most cooking is around 350 degrees (f), do not select a Low smoke points oil.  many will argue bacon grease over vegetable oil, or coconut oil over cottonseed, but truth is, they all work as they are all higher smoke points.   While Avocado and Coconut (refine) have the highest smoke points, any oil with 350 degrees (f) will provide a sufficient finish. If the item comes out sticky, just reheat and cool again as most often, a sticky finish is because you either did not reach smoke point or did not heat long enough.

Can I cook all foods in Cast Iron?   While quality cast iron cookware often comes preseasoned, some manufactures recommend to cook fatty items for first time to assist giving it a greater protective finish.  non-preseason cookware must be seasoned before use.  Food items like citrus along with tomato-based products are not recommended for the first use of your new kitchen piece, although we have cooked tomato sauces with Lodge preseason cookware without any difficulties.  We recommend always well seasoning all new non season products and with a new preseason, it does not hurt to lightly coat some oil and preheat for about 15 minutes before first time use.  SEASONING

Cast iron needing restoring:    One of the greatest thrills to cooking on cast iron not only comes from the food we eat, but through the purchase of unique finds often at theft stores.  Sometimes old, rusty and collectable and sometimes, covered in excessive patina finishes that are uneven, flaking or sticky.  They are well worth restoring removing the rust or unwanted finish and reseasoning to look just like new. Check out Restoring:

Smoke Point Chart

OIL TYPES -Quality		Smoke Points

Almond oil		420°F	216°C
Avocado oil	Refined	520°F	271°C
Avocado oil	Un-Refined, Virgin	375-400°F	190-204°C
Butter		250–300°F	121–149°C
Canola oil	Expeller Press	375-450°F	190-232°C
Canola oil	High Oleic	475°F	246°C
Canola oil	Refined	400°F	204°C
Castor oil	Refined	392°F	200°C
Coconut oil	Extra Virgin (Unrefined)	350°F	177°C
Coconut oil	Refined	450°F	232°C
Corn oil	Unrefined	352°F	178°C
Corn oil	Refined	450°F	232°C
Cottonseed oil		420°F	216°C
Flax seed oil	Unrefined	225°F	107°C
Ghee (Indian Clarified Butter)		485°F	252°C
Grapeseed oil		420°F	216°C
Hazelnut oil		430°F	221°C
Hemp oil		330°F	165°C
Lard		370°F	188°C
Macadamia oil		413°F	210°C
Mustard oil		489°F	254°C
Olive oil	Extra virgin	375°F	191°C
Olive oil	Virgin	391°F	199°C
Olive oil	Pomace	460°F	238°C
Olive oil	Extra light	468°F	242°C
Olive oil, high quality (low acidity)	Extra virgin	405°F	207°C
Palm oil	Diffractionated	455°F	235°C
Peanut oil	Unrefined	320°F	160°C
Peanut oil	Refined	450°F	232°C
Rice bran oil		415°F	213°C
Safflower oil	Unrefined	225°F	107°C
Safflower oil	Semi-refined	320°F	160°C
Safflower oil	Refined	510°F	266°C
Sesame oil	Unrefined	350°F	177°C
Sesame oil	Semi-refined	450°F	232°C
Soybean oil	Unrefined	320°F	160°C
Soybean oil	Semi-refined	350°F	177°C
Soybean oil	Refined	460°F	238°C
Sunflower oil	Unrefined	437°F	225°C
Sunflower oil	Semi-refined	450°F	232°C
Sunflower oil, High Oleic	Unrefined	320°F	160°C
Sunflower oil	Refined	440°F	227°C
Tea seed oil		485°F	252°C
Vegetable shortening		360°F	182°C
Walnut oil	Unrefined	320°F	160°C
Walnut oil	Semi-refined	400°F	204°C

NOTES: Why do I not use some oils. 

The key to understanding this paradox is looking at the concept of “Smoke Point.”  The Smoke Point is literally the point at which oil starts to smoke.  Different oils smoke at different temperatures; olive oil is one that generally does best at Low to Medium heat.  Much hotter, and it too may smoke.  Smoke when cooking is not a good thing—the oil is decomposing under the extreme heat, and the antioxidants we usually love in olive oil are replaced by free radicals and other dangerous molecules.  The smoke itself is also toxic and shouldn’t be breathed.  Finally, when there’s smoke, it means the oil is dangerously close to its “Flash Point” meaning the point at which it may catch on fire!  When seasoning a cast iron skillet, we heat the item reaching the oils smoke point, but in cooking, one wants to stay below the oil smoke point.


PEANUT OIL:  If you do not have any allergy to peanuts, and you are not cooking for the public, there is no risk using peanut oils which are great for deep frying. According to the Food Allergy Anaphylaxis Network, “Studies show that most allergic individuals can safely eat peanut oil (not cold pressed, expelled, or extruded peanut oil - sometimes represented as gourmet oils).” They recommend that allergic individuals consult a physician regarding whether or not to avoid peanut oil. Therefore, due to some folks having peanut allergies, I do not select to use it.  However,  highly refined peanut oil is different from peanuts, peanut butter, and peanut flour when it comes to allergy. This is because most peanut oil undergoes a refining process, in which it is purified, refined, bleached, and deodorized. When peanut oil is correctly processed and becomes highly refined, the proteins in the oil, which are the components in the oil that can cause allergic reaction, are removed. This makes the peanut oil allergen-free! The vast majority of peanut oil that is used in food service and by consumers in the U.S. is processed and is considered highly refined. Nevertheless, it requires reading the label to ensure you selected an allergy free oil.

Flaxseed:  The University of Maryland Medical Center warns that flaxseed can slow down the rate at which your body absorbs oral medicines. Furthermore, since Flaxseed is unsaturated, it can be damaged by exposure to light or heat and should be kept in a cool, dark place. It should not be used for frying as direct exposure to heat will destroy the oil's natural benefits, although controversy argues this would also happen eating cooked salmon for it's rich vitamin benefits. Unlike, fish, flaxseed oil breaks down under heat and since cast iron cookware is used above the smoke points of flax oil, then it leaches just as scratched t-fal would into foods.  Instead, use the oil in salad dressings, sprinkle on hot or cold pasta and vegetables, or add to mashed potatoes.  You can also use it in making spreads and dips or mix with margarine. Products that may contain flaxseed  include cereal, bread and other baked goods. Folks who are diabetic or schizophrenic may not be able to absorb the beneficial fatty acids from flaxseed and should use fish oils instead.  So I choose to not cook with nor season any cookware with this oil as the oil was never meant to be used heated.  Additionally, it cost so much more even over olive oil that I'm not wasting my dime.

Only one advocate mentions the use of flax's in seasoning.  It will make a very dark and dry surface on cast iron. Although, is it better for seasoning than the rest?   A group called "Cast Iron Cookware" did a study using flaxseed oil on a skillet. They also did a second skillet using bacon grease. The results, well both make the pan very dark. The bacon grease, however, seem to work better having better non-stick benefits and the finish lasted longer. Additionally, the group did not like the expensive cost of flaxseed.  This same advocate promotes that everyone else is doing it wrong. Including your great grandparents.  They also state that Potjie cures their cast iron using flax oil.  Potjie does not claim this as they merely state the use of vegetable oil.  Although an Asian Importer of Potjie uses the statement as a market statement which the manufacture does not claim.   Additionally, in every health study towards the use of flaxseed, the product is used cold and not as a cooking oil or heated. Flaxseed meal and flaxseed oil are not the same either. While flax oil has many benefits, it also needs more studies before I become a believer that it makes a good seasoning coat for my cast iron. (Medical Information Mayo Clinic)  Since medical science states that seasoning oils just as the irons in cast iron can leach into foods you cook, the answer for me is simple. "I don't use it."

Olive Oil: I often cook with Olive Oil, although, like any oil, temperatures must remain below smoke point. The term “extra-virgin” means the same thing as “first cold pressed” and is the best quality of olive oil.  “Virgin” means it may have more acid, but is still pretty tasty and good quality.  However, the USDA does not legally recognized its classification system (i.e. extra-virgin) defined by the International Olive Oil Council (IOOC) .  Technically, the US still uses a system created in 1948 that lists olive oil grades as "Fancy," "Choice," "Standard," "Substandard."  According to Dr. Kristina Lewis of Asheville, NC  "Technically, until the US adopts the IOOC standard, the term “extra virgin” can be listed on any label of oil, and it doesn’t have to mean anything!"   Although, while I do not use olive oil for seasoning, it does seem to make a good conditioner wiping down a piece of cast iron after you used it, washed it and ready to store.  It's also cheaper than cast iron conditioners being sold on the market.

Canola Oil:

Canola Oil also has high amounts of health-promoting Omega-9 monounsaturated fatty acids, just like olive oil, as well as relatively high Omega-3 levels.  Canola oil seems to have a higher Smoke Point and thus can be used more reliably for higher-heat cooking compared to olive oil.  Caution for canola oil should be exercised due to its content of Linoleic Acid, an Omega-6 Polyunsaturated Fatty Acid (PUFA).  Excessive PUFA intake, especially Omega-6 fatty acids, is rampant in today's diet due to it's inclusion as part of artificial and processed foods.   Oils such as safflower (78%), grape seed (73%), sunflower (68%), corn (59%), cottonseed (54%), and soy (51%) have the highest degree of PUFA. Compared to these other oils, canola is a better choice with a lower percentage of PUFA overall at 21%.  Olive oil is only 10% PUFA, while coconut oil and butter are the lowest at 2%.

In truth, expeller-pressed, organic canola oil is not be feared.  Just try to limit your intake to a few times per month because in general, "everything in moderation" is the best rule for a balanced and healthy diet.

Summary:  Our parents, grandparents and surely our great grandparents never made a fuss about what oils to use and most have surely outlived the younger generations.  They ate well, they used cast iron and ate less fast or processed foods.  Put more thought into what your going to cook and stop worrying about what seasons best or worst.  What is important is the joy of food, sharing recipes and appreciating a piece of cookware that likely will also outlive most of us by several generations.

Here's a post video I receive from a reader: Check it out and see what this Rancher thought of our restoration process.  Using the simple vinegar and water 50/50 mix, it takes little effort to make rusty skillets look clean again:   He mentions using some bacon, then states maybe will use some CRISCO.  Although, I do not know which he used but both will get the job done.



After seasoning, look how nice these came out not having to use any special tools or much effort:

return to recipes: 

return to Chuck Wagons:

return to cowboy and chuckwagon cooking: