Cast iron cookware is incredibly versatile and long-lasting. They can last for generations, But only if you take proper care of it. I’ve cooked on cast iron for years — from brand-new pans fresh out of the box to my grandmother’s skillet that’s seen more breakfasts than I can count. Trust me, a well-seasoned pan can outlive us all.
Seasoning isn’t just a “nice to do” step — it’s what separates a sticky mess from that smooth, glossy surface every cast iron lover brags about. But the question is: which oil should you use for seasoning? This is where most people get confused.
Nowadays, there are plenty of new products specifically designed for seasoning cast iron. Many brands even sell their own seasoning oils. Others swear by old family methods, claiming nothing can beat those.
I’ve tried a few of those old-school tricks myself, bacon grease and lard and while they’re nostalgic, modern oils do a far better job. Meanwhile, food scientists on the internet keeps producing new “best oil” debates.
Let’s explore what makes an oil ideal for seasoning cast iron and the qualities it should have to get the best results.
What is seasoning and why is it important?
So let’s start with the basics. Seasoning essentially means applying a layer of oil or fat to cast iron and heating it to its smoke point.
Most folks do it in the oven because it gives you even heat and steady results, no guessing games. It serves two key purposes: protecting the cast iron from rust and creating a naturally non-stick surface.
While many manufacturers now sell pre-seasoned pans, it’s still a good idea to season them yourself after the purchase. This simple process—coating the cast iron in oil and heating it—significantly enhances its durability and extends its lifespan.
Every time you cook with oil, you add another thin layer of seasoning. The most-used pan lasts the longest. That’s why old cast iron in antique stores looks amazing — it’s been cooked on for decades, layer after layer of seasoning baked right in.
What Happens During Seasoning?
When oil is heated past its smoke point, its fatty acids break down (oxidize) and bond to the iron, forming a protective layer. This entire process is called polymerization, and it’s what creates the seasoning on your pan.
Think of it like armor for your skillet — every layer of oil you heat turns into a protective shield that fights rust and makes food release easier over time.
What to look for in a cast iron seasoning oil:
Now that we understand that any oil or fat will polymerize when heated, the question is: why are some oils better suited for this process than others? Here’s where people get it wrong, not all oils are created equal. Some bond beautifully to iron; others flake off faster than a bad paint job.
Let’s dive into the factors that make an oil ideal for seasoning cast iron.
High smoke point:
The smoke point of an oil is the temperature at which it starts to release smoke, and its molecules begin to break down. This is where the polymerization happens.
An important point to note is that you should choose an oil with a smoke point higher than your usual cooking temperature. For example, if you sear steaks at 400°F, you should season your skillet with an oil that has a smoke point above 400°F. This ensures that the seasoning stays intact during high-heat cooking and doesn’t flake off or break down. So, the higher the smoke point the better.
More unsaturated fats than saturated fats:
Choose oils with a higher ratio of unsaturated fats compared to saturated fats. Unsaturated fats are the ones that form the seasoning layer during the polymerization process. Oils rich in unsaturated fats are the most optimal choice for seasoning cast iron.
Unsaturated fats are your best friends here — they’re flexible enough to form those tough polymer bonds. It’s science doing you a favour.
Affordability and availability:
These two factors are also important to consider. In the old days, people often used lard or bacon fat for seasoning because options like grapeseed or canola oil weren’t readily available. These days, we’ve got shelves full of options but you don’t need to overthink it. Pick something reliable, affordable, and easy to find.
We should also keep in mind to choose an oil that’s affordable and versatile enough to use in other cooking as well, not something you buy solely for seasoning and never use again. Practicality matters.
Neutral flavour:
If the oil you’re using isn’t neutral in flavour, the food you cook in that pan will carry the oil’s taste. That’s why you should use a neutral-flavoured oil—it not only avoids altering the flavour of your dishes but also makes the oil more versatile for other purposes, like salad dressings.
Refined oil:
One last tip: always go for refined oils. They handle heat better, have higher smoke points, and won’t leave sticky residue behind.
What seasoning oil do manufacturers suggest for cast iron?
Most cast iron skillets these days come pre-seasoned from the manufacturers, and many manufacturers also provide their own oils specifically for seasoning. I check what manufacturers recommend. After all, these companies live and breathe cast iron and they’ve tested thousands of pans.
Let’s explore whether most manufacturers recommend a particular type of oil for seasoning.
“Lodge recommends vegetable oil, melted shortening, or canola oil”
– Lodge Cast Iron
“We’ve long advocated for grapeseed oil — it’s what we use to pre-season every Field Skillet”
– Field Company
“Pre-seasoned with organic flaxseed oil, our cast iron seasoning improves with every use and near non-stick performance out-of-the-box”
– Finex Cast Iron Cookware Co.
“We recommend flaxseed or grape seed oil”
– Nest Homeware
“We prefer refined canola, but any refined variety will do”
– Butter Pat Industries
Even major brands don’t fully agree. That’s because seasoning isn’t an exact science, it’s about what works best for how you cook.
Most manufacturers recommend grapeseed or flaxseed oil for cast iron seasoning.
The best oil for seasoning cast iron:
Avocado oil:
Avocado oil is the best oil, and it’s my top choice for cast iron seasoning. Now we know the parameters to judge a good oil for seasoning: its smoke point, being largely neutral in flavor, availability and affordability, and having a high unsaturated fat content.
Avocado oil meets all these criteria. I’ve even seasoned the griddle of my Grilla Grill Primate with Avocado oil and the seasoning holds beautifully.
It has one of the highest smoke points of commonly available cooking oils (between 480 and 500°F) which is ideal for any kind of cooking, and it’s reasonably priced on platforms like Amazon and Walmart ($8 for 48 ounces, at the time this article was written). It also has a high amount of unsaturated fats, is neutral in flavor. It’s also versatile enough for everyday cooking.
Grapeseed oil:
Now let’s talk about the top-recommended oil by manufacturers. Grapeseed oil is also a great option and has long been considered the best oil for seasoning by food scientists. Many manufacturers who provide their own seasoning oils also include it in their formulations. I’ve used it to season my pans to cook recipes like sticky stove top chicken wings and it works just fine.
But in terms of smoke point (420°F) and unsaturated fats, avocado oil is superior. Still, it’s hard to argue with the results. If you’re re-seasoning often or just starting out, grapeseed oil is a safe bet.
Both oils are neutral in flavor and affordable (find it on Amazon for 5$ for a 24-ounce bottle). There’s nothing wrong with using grapeseed oil—it’s just not as good as avocado oil for seasoning.
Flaxseed oil:
Many people believe flaxseed oil is the gold standard for seasoning oils, I disagree. You’ve likely come across claims online that it’s the best option for cast iron seasoning, but that’s mainly because it’s a “drying oil,” meaning it forms a patina layer much faster during the seasoning process. Its smoke point is very low (225°F), making it unsuitable for high-temperature cooking.
While a flaxseed-seasoned pan may look great, if you plan to use your pan extensively, its seasoning tends to flake off with frequent use and high-heat cooking. That’s why opinions are divided. I fall somewhere in between — great for restorations, not my daily go-to.
Here’s how these three oils stack up against each other:
| Oil | Smoke Point | Unsaturated Fat | Best For |
|---|---|---|---|
|
Avocado Oil (My Top Pick) |
480–500°F |
High |
Seasoning and high heat cooking |
|
Grapeseed Oil (Second Best) |
420°F |
High |
Regular seasoning and cooking |
|
Flaxseed Oil |
225°F |
Very High |
Low-Medium heat cooking. It is high in unsaturated fats, but low smoke point does not make it ideal for seasoning |
Other options for seasoning cast iron:
The three oils described above are my top picks for cast iron seasoning, and most manufacturers and experts also lean towards these options. I’ve been using them for quite a while and shared my thoughts on them. However, we do have other options available as well. Let’s talk about those too. Because if there’s one thing I’ve learned, is that the “best” oil is the one you’ll actually use.
Olive oil:
The easiest-to-find oil might already be in your pantry. However, it’s likely to be extra virgin olive oil (smoke point around 350°F). If you want to use olive oil for cast iron seasoning, look for its refined version (with a smoke point of 465°F). Still, there are better options available, as discussed earlier. Save this one for salad dressings instead.
Lard or bacon fat:
In the old days, refined oils weren’t readily available. If you ask your grandmothers, they’ll tell you they seasoned their cast iron cookware their whole lives with lard or bacon fat. Even today, many people claim nothing works better for seasoning. However, we now have much better options.
The main issue with lard or bacon fat is their high saturated fat content, which isn’t ideal for the polymerization process. Additionally, a pan seasoned with these fats can turn rancid between uses.
Canola or vegetable oil:
Vegetable oil and canola oil are inexpensive, and many people use them for seasoning their cast iron. Their smoke points aren’t bad either (400–450°F for both), and they’re readily available and affordable. Plus, they have many multipurpose uses. However, I still believe the oils we discussed earlier are better options.
Now that we’ve covered the good stuff, let’s talk about what to leave on the shelf.
What not to use for seasoning your cast iron?
Now that we have developed what works best for cast iron seasoning and what will work well enough if you don’t have the preferred oils, now lets talk about what not to use for cast iron seasoning.
Coconut oil:
Coconut oil isn’t very neutral in flavour, and its main issue is its high saturated fat content, which doesn’t help with the polymerization process. Because of this, it won’t do much for seasoning. Coconut oil has plenty of other uses and benefits, but personally, I don’t prefer it for cast iron seasoning.
Butter:
Butter should not be used for this purpose. For every advantage we can list for oils and fats used for seasoning, we can count just as many disadvantages for using butter. First, its smoke point (350°F) is very low. Second, its high saturated fat content is not ideal.
As I mentioned earlier, we should avoid using anything containing animal fats for seasoning. The same principle applies to items with milk or dairy products, as they can turn rancid very quickly. Use butter for toasting or searing, not for seasoning (Besides, butters for pancakes not protecting your cookware).
Final verdict:
I’ve listed my top options, with avocado oil being my favourite for cast iron seasoning. So that’s where I land after years of experimenting, a few mistakes, and a lot of perfectly fried eggs.
Grapeseed and flaxseed oils can be considered solid second-best choices. As for the other options, we’ve gone over their pros and cons as well.
The truth is, any oil or fat will create a seasoning layer on your cast iron. Every time you cook with oil, a layer of seasoning is added to your skillet. The most durable and well-seasoned pan is the one that’s used the most. Some oils, however, create a better seasoning layer than others. And now, you know what makes a good oil for seasoning cast iron.
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