What Is the Best Oil for Seasoning Cast Iron
Seasoning cast-iron for some reason puts fear into most people when, in fact, it is a simple task. Choosing the correct oil to season the iron with is another hurdle those new to cast-iron cooking also have to overcome. So what is the best oil for seasoning cast iron?
Grapeseed oil is the best oil for seasoning cast iron due to its ability to withstand the high smoking points required for polymerization. Other recommended oils include flaxseed oil, vegetable oils, canola oil, and seasoning produced by the cast iron manufacturers themselves.
A high smoking point is what is required for polymerization, which is the process of oil being baked onto a cast iron’s surface. This is a natural process providing a non-stick surface that also prevents iron rusting.
What Is Seasoning oil?
Cast iron seasoning oil is a product that you can use to season your cast-iron pans. To name a few oils: olive oil, grapeseed, flaxseed, soybean, corn oil, vegetable shortening, and lard.
Seasoning creates an invisible, protective layer of polymerized fat on the surface so it won’t stick or rust as easily when exposed to water and other substances.
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What Is the Best Oil for Seasoning Cast-Iron
This is the brand of Grapeseed Oil that I am able to obtain easily. It is expensive but I have found that Grapeseed oil is becoming more readily available and the price is coming down. I have found a 3-liter bottle available at Amazon for a great price – check that out here.
Flaxseed oil is another oil that is highly recommended for seasoning. If you use nut or vegetable oils they need to be pure and refined.
Any oils that have been modified to become Light, Virgin, or Unrefined have a much lower smoking point. Unfortunately, these are the oils that are generally available to us these days, not the pure version of the oil. These modified oils are the ones that quickly become rancid.
Cast iron has been around for many centuries. Our forefathers would not have had easy access to vegetable oils, nut oils, and the like.
I dare say that they would not have even seasoned their cast iron cookware.
Their cookware would have seasoned itself purely by cooking meat within the cast iron every day. Wala beautifully seasoned cookware the natural way.
Why Is a Seasoning Oils Smoking Point Important?
To keep your cast iron cookware well protected, the oil needs to reach its smoking point before it can polymerize and form a protective barrier. In order for this process to take place you’ll need to know an oil’s smoking point so that heating up your pan will be as effective.
Understanding Cooking Oils
Cold Pressed Oil
Pressed oils are created by using a mechanical press to extract the oil from seeds. The end product of this process is high-quality plant fat made up of no cholesterol that has been protected against oxidation in order for it to last longer on the shelf without having any rancid taste.
Unrefined & Refined Oils
The oils we use in cooking and seasoning are separated into two categories: unrefined and refined. Unrefined oil is lightly filtered to only filter out the largest particles, while refined ones go through a much more complex process of filtering that removes even microscopic pieces from the oil.
Saturated Fats & Unsaturated Fats
Some of the most common saturated fats include lard, suet, tallow from cows, and sheeps’ fat.
Unsaturated fat is a type of lipid that is usually liquid at room temperature such as vegetable oil-based spreads like margarine.
When you’re cooking with oils, it is best to use unsaturated fats. They are more reactive and polymerize better when seasoning your dish! The same applies when seasoning or protecting your cast iron unsaturated fats are better at polymerizing when seasoning than saturated fat.
Monounsaturated Fats
Monounsaturated fats have one double bond, which makes them more stable than polyunsaturated and saturated fat.
Polyunsaturated Fats
Having a higher percentage of double bonds (up to 6) polyunsaturated fats creates a better and longer-lasting protective coating for cast iron.
Top 11 – Cast-Iron Seasoning Oils (Table)
This table outlines the best seasoning oil all the way down to the ones that will do the job but not give you a sustainable seasoned finish.
| Best | Oil | Saturated Fat | Poly-Unsaturated Fat | Mono-Unsaturated Fat | Smoke Point | Oven Temperature |
|---|---|---|---|---|---|---|
| 1 | Grapeseed | 10.5% | 74.7% | 14.3% | 421 °F | 441 °F |
| 2 | Flaxseed | 9.0% | 68.0% | 18.0% | 225 °F | 245°F |
| 3 | Corn | 12.9% | 54.7% | 27.6% | 450 °F | 420 °F |
| 4 | Canola | 7.4% | 28.1% | 63.3% | 460 °F | 480 °F |
| 5 | Vegetable | 14.0% | 33.0% | 48.0% | 450 °F | 470 °F |
| 6 | Avocado | 11.6% | 13.5% | 70.6% | 482 °F | 502 °F |
| 7 | Olive | 13.8% | 10.3% | 73.0% | 380 °F | 400 °F |
| 8 | Vegetable Shortening | 25.0% | 28.0% | 41.0% | 410 °F | 430 °F |
| 9 | Bacon Grease | 32.0% | 11.0% | 41.0% | 394 °F | 394 °F |
| 10 | Lard | 39.0% | 11.0% | 45.0% | 374 °F | 394 °F |
| 11 | Coconut | 87.0% | 1.8% | 6.0% | 400 °F | 420 °F |
What Kind of Oil Do You Use to Season a Cast Iron Skillet?
Regardless of the type of cast-iron, you want to season you can use the same oil that you would use for your cast-iron skillet.
You can use a refined pure oil such as the Grapeseed Oil outlined above. Alternatively, you can choose a purpose-made cast-iron seasoning like the cast-iron oil pictured below.
Purpose Made Cast Iron Seasoning
If you just want to get the job done and not figure it out for yourself. Click on the image below to head over to Amazon for Caron & Doucet Cast Iron Seasoning Oil and Conditioner. Made from 100% plant-based refined coconut oil.
If you want more information regarding various oils used for seasoning you should continue to read below.
Signs That Your Cast Iron Cookware Needs Seasoning
If you have food sticking to your cast iron it means that the seasoning has broken down. There is not enough of a barrier there to stop the food from adhering to the pores of the iron.
Which then, in turn, burns the food into the pores and makes a sticky mess.
This is when an arduous cleaning process is required. Followed by a complete reseasoning process.
If a regular seasoning process is carried out it can stop a major cleaning and seasoning process from being required.
Nut Oils or Vegetable Oils for Seasoning Cast Iron
You now have an understanding of the different properties of oils as well as what is required to ensure your cast iron seasoning reaches its “Patina” (its smooth shiny non-stick surface). Check out the oils below to help you choose the seasoning oil that is right for you…
Olive Oil
Pure Olive oils’ smoking point is 410 degrees Fahrenheit or 215 degrees Celsius.
Cold-pressed “virgin” and “unrefined” 320 degrees Fahrenheit or 160 degrees Celsius.
Is olive oil good for seasoning cast iron? I would not choose olive oil due to its low smoking point. Basically, you cannot the oil into the pores of the cast iron because it burns off too early.
It is a great choice of oil to cook with once your cast-iron is seasoned correctly. It will help keep your irons “Patina” in good shape.
See my article here that dives deep into the olive oil and cast-iron combination.
Peanut Oil
The smoking point is at 450 degrees Fahrenheit or 235 degrees Celsius.
The Chinese use peanut oil to reach high temperatures when searing and stir-frying and it retains its flavor when used in this fashion.
Cold-pressed “virgin” and “unrefined” 320 degrees Fahrenheit or 160 degrees Celsius.
Almond Oil
Refined – the smoking point is 495 degrees Fahrenheit or 255 degrees Celsius. This oil can give your cast iron a durable finish.
But you are likely only to be able to find “unrefined” oil which as with some of the other nut oils cannot be heated to high temperatures.
Avocado Oil
I have recently been testing out avocado oil. I have been using it for my high-temperature searing and stir-fries. So I thought I would give it a go.
I will revise this post when I am 100% certain I would recommend this oil for seasoning.
One amazing find is that – after cooking in avocado oil is that there is always oil left in the bottom of the pan. Almost all other oils dissipate “just like water”. I pour the leftover oil over the prepared dish it tastes divine.
REVISED 2021: I have been testing seasoning and cooking in organic avocado oil due to its high smoking point and its ability to fight rancid properties. While I am still using lashings of Avocado Oil for cooking and particularly frying in my cast-iron I am currently seasoning my cast-iron with high-quality Grapeseed Oil.
Grapeseed Oil
Is grapeseed oil good for seasoning cast iron? Yes, grapeseed oil is my oil of choice for seasoning my cast-iron.
Refined Grapeseed Oil has a high smoking point at 480 degrees Fahrenheit or 250 degrees Celsius and is extremely resistant to breaking down.
But you should be very wary of the words “cold-pressed” and “virgin” as these have been designed for not only cooking but to be used as “gourmet” in dressing, desserts, and the like. They have a much lower smoking point.
Flaxseed Oil
Flaxseed oils’ smoking point is 225 degrees Fahrenheit or 107 degrees Celsius which is not very high. It should be noted that unused oil will go rancid if not used quite quickly.
Flax oil is a drying oil that makes it perfect for seasoning cast iron pans. It’s comprised of 68% polyunsaturated fats and 86% unsaturated fats, making this the best choice in oils to season your pan with.
Coconut Oil
Refined (pure) oil can be heated as high as 450 degrees Fahrenheit or 232 degrees Celsius.
Is coconut oil good for seasoning cast iron? Even though coconut oil has an extremely low oxidation factor it is highly durable as a frying oil, even more, durable than beef tallow.
Virgin oil has to be kept below 350°F/175°C so you should be very wary again of what you are purchasing.
Corn Oil (Maize)
Refined corn oil can be heated as high as 450 degrees Fahrenheit or 235 degrees Celsius.
Cold-pressed “virgin” and “unrefined” 320 degrees Fahrenheit or 160 degrees Celsius this oil will not do the job of seasoning cast iron.
Rapeseed Oil (Canola)
This oil is particularly a great seasoning for when your cast iron is to be stored for long periods of time. A resin finish can be achieved which protects the cast iron while in storage. You should also be prepared for a pungent odor in the kitchen after seasoning with this oil.
Heat cast iron in the oven at approximately 250 degrees for 2 hours. Then wipe a light coating over the iron, cook for 45 minutes to 1 hour. Apply and cook a least one more time.
When the iron has cooled wipe over to remove any excess before storage.
Rapeseed Oil can be heated as high as 400 degrees Fahrenheit or 200 degrees Celsius.
Cold-pressed “virgin” and “unrefined” 225 degrees Fahrenheit or 110 degrees Celsius.
Safflower Oil
Refined safflower oil can be heated as high as 510 degrees Fahrenheit or 265 degrees Celsius.
Cold-pressed “virgin” and “unrefined” 225 degrees Fahrenheit or 110 degrees Celsius.
Sesame Oil
Refined sesame can be heated as high as 450 degrees Fahrenheit or 210 degrees Celsius.
Cold-pressed “virgin” and “unrefined” 320 degrees Fahrenheit or 160 degrees Celsius.
Soybean Oil
Refined and high oleic soybeans’ smoking point is 450 degrees Fahrenheit or 235 degrees Celsius.
The cold-pressed “virgin” and “unrefined” smoking point is 320 degrees Fahrenheit or 160 degrees Celsius.
Sunflower Oil
Refined and high oleic sunflower oils smoking point is 450 degrees Fahrenheit or 235 degrees Celsius.
“Virgin” or “cold-pressed” sunflower oils have a very low smoke point and should not be for seasoning cast iron. Sunflower oil will go rancid quicker than olive oil or canola oil.
Cold-pressed “virgin” and “unrefined” 225 degrees Fahrenheit or 110 degrees Celsius.
Walnut Oil
The refined version of walnut oil has a smoking point of 400 degrees Fahrenheit or 204 degrees Celsius which I don’t believe is high enough to season cast iron. But you could give it a go if you can get your hands on pure refined walnut oil.
The common walnut oil you will find is unrefined and can be used for frying at low temperatures, but usually, it is used for salad dressings.
Cold-pressed “virgin” and “unrefined” 320 degrees Fahrenheit or 160 degrees Celsius.
Crisco
Is a genetically modified oil and lard is increasingly being used in the favor of the manmade variety.
Animal Fats
Pig Fat (Lard)
Lard has a smoking point of 360 degrees Fahrenheit or 185 degrees Celsius.
Lard soaks into the pores of the iron when applied warm and liberally.
It also works wonders if you have to repair a rusty piece of cast iron cookware.
Bacon Grease
This grease has a smoking point of 360 degrees Fahrenheit or 185 degrees Celsius.
You apply bacon grease by rubbing a fatty piece of bacon over the cast iron.
When applying the bacon to the iron you will find it difficult to get the grease into the surface areas. So you will not be able to fully season the iron.
Arguments are out there that the salt in the bacon grease will pit the iron.
Duck and Goose Fat
Unfortunately as flavorsome as these lovely fats are they only have a very moderate smoking point which is 375 degrees Fahrenheit or 190 degrees Celsius.
To continue to use these for your awesome potatoes but not for seasoning your cast iron.
Bear Fat and Deer Fat
If you are happy to eat bear and deer meat why not utilize the fat as well. Just rub the fat over the Dutch oven and season as you normally would any other oil.
Dairy Fat
Butter
Butter should only be used over very low heat. Whole butter has not only saturated fats but milk protein and oils from the cream during the churning process.
Unfortunately, when the butter gets too hot it turns brown and then burns very quickly. You would be left with a very bitter-tasting seasoning.
Just think of all the recipes that require butter for its moist browning properties.
So that rules this seasoning out as it cannot tolerate the high temperatures required to season cast iron.
If you have had an accident and need some help to clean up your Dutch oven check out this article on how to clean a Dutch oven after cooking. Here.
Mineral Oil
It is great for making wood utensils and cutting board water-resistant. Should not be used to season cast iron.
Vegetable Oils – The Verdict
The following oils will go rancid very quickly when heated at heat temperatures. This is mainly because these oils are not generally available as refined products.
They are high in polyunsaturates because they have been manufactured to become “Virgin” Or “Cold Pressed”. They are suitable to use at low temperatures or in salad dressings and the like.
The Oils Are:
Sunflower, Olive, Soybean, Canola, Safflower, Sesame, Peanut, and Walnut.
Some believe that because vegetable oils are much more liquefied than animal fats these oils get into the pores of the cast iron.
Due to the fact that the pure versions of these oils are not readily available I would stay away from them. Unless you can get a hold of pure oil.
Many have used Crisco in the past but due to genetic modifications, they have turned to more natural and untouched oils. Coconut oil for seasoning cast iron is my first choice if using vegetable or nut oils.
I would suggest that if you want to use vegetable oil and can source a pure oil that can withstand high temperatures go ahead and season your cast iron with it.
The next best vegetable oil would probably be Canola.
Animal Fats – The Verdict
As our ancestors did not have access to genetically modified food sources, I believe they used animal fats in their cast iron only.
This cookware still exists in various forms and is being used today by many around the world.
Bear in mind that it may not be kosher! So if you are preparing food for others something to consider…
Grease Keepers
Who remembers back in the day your grandmother using a grease keeper? My grandmother certainly did not have any spare change to purchase fats or oils.
So she kept all cooking oils and fats in her grease keeper.
I do remember as I got older she started to buy lard. This was only when she was not cooking for the whole family any longer so she didn’t have a good supply of drippings.
The one I use is similar to the one below – mine is an heirloom piece made from ceramic.
Money-Saving – Recycle Cooking Oil
Using a grease keeper will save you money if you save and reuse your own grease from cooking.
Frequently Asked Questions
Quick answers to some of the many frequently asked questions that surround seasoning cast iron and what the oils and processes are.
What Is Seasoning Oil?
Seasoning oil is an oil used to protect the cast iron from rusting. It is also used to season cast iron as a non-stick barrier is built up over time so the cast iron effectively becomes a non-stick pan.
Should You Season Cast Iron After Every Use?
No, you do not need to season cast-iron after every use. Season your cast iron before its first use. Then reseason it when your dishes start to stick to the bottom of the pot, pan, or skillet. Or when you notice the Patina is becoming dull.
I am also asked frequently how many times should I season my cast iron? There is no limit to seasoning cast-iron. Just season when it becomes dull and food starts to stick to it.
How Many Times Do You Season a Cast Iron Skillet?
Generally three to four times during the seasoning process. The caveat being how well the non-stick “Patina” (surface) is intact. If your food is sticking repeat the process until you see a shiny black surface. If your food is releasing once or twice should do it.
How to Season Cast Iron
The cast iron needs to been cleaned and thoroughly dried before any seasoning is applied to its surface.
You can then apply a thin layer of the oil of your choice over the surface of the iron. Making sure to apply it to the underside, lid, and handles.
Ensure your oven has a tray or aluminum foil place under where the iron will be set in the oven. Invert the cast-iron and its lid on a middle oven rack at 450°F.
Bake the iron for approximately one hour.
Let it cool in the oven and repeat if necessary.
How to Clean a Rusty Cast Iron Dutch Oven
Before any type of seasoning can be applied to cast iron it must be clean and dry. So if you have a rusty dutch oven check out my article here. It will give you the quick steps you need to get the cast iron ready for seasoning.
Final Thoughts – What Is the Best Oil for Seasoning Cast Iron?
There are a couple of great points that have emerged:-
- People who use their cast iron regularly have better-seasoned iron due to the fact that the oils from the dishes they prepare are seasoning the cast iron themselves.
- Save money by saving your “drippings” as I remember them being called.
Me I’m all for the least touched by man. I’m for full fat, fresh produce, hearty food purchase, preparation, and cooking. Taught to me by my relatives.
My grandparents lived to 94 and 93 (mum’s side) and 89 and 90 (dad’s side).
Don’t get me wrong they too fell prey to the low fat no fat craze until they got hungry.
“My personal favorite oil for cooking is organic avocado oil. Due to its high smoking point and its ability to fight rancid properties. Another interesting fact about cooking in avocado oil is that when your food is fried there is always oil left at the bottom of the pan. I then use this oil and pour it over my cooked dish it tastes divine”.
“Remember I am currently using a high-quality Grapeseed Oil to season my cast-iron cookware.
Also remember these words should be stated on any bottle “organic”, “extra virgin”, “unrefined” and “cold-pressed” this is the one I use here.
I believe that if it is good enough to cook and eat them, it is good enough to season our cast iron with.
I would love to thank Clove Garden for its extensive research into all things oil. You can visit them here for a wealth of information regarding oils and much more.
Looking for a new cast iron Dutch oven and want to research a little more? Check out these cast-iron Dutch ovens that I have reviewed in-depth here.
Recommended Reading
Learning how to season a cast-iron Dutch oven is simple – check out this article I have written that makes the process simple and quick.
One-Pot Cooking Rocks
Thanks for the video music – Ben Sound
