Cast iron cookware are incredibly versatile and long-lasting. They can last for generations. But that’s only possible 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 the secret that separates a frustrating, sticky mess from that smooth, glossy surface every cast iron lover brags about. But the big 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. Some manufacturers have even introduced their own oils for this purpose. Then there are people who swear by their family’s traditional methods, claiming nothing can beat those. I’ve tried a few of those old-school tricks myself — bacon grease, lard, you name it — and while they’ve got nostalgia going for them, modern oils do a far better job. Meanwhile, food scientists on the internet keep coming up with new recommendations for the “best” oil.
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 — because understanding what seasoning is makes every other choice easier. 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 on your cast iron skillet, polymerization happens. So, every time you cook with it, you’re basically seasoning it. The pan that is the most used is the one that 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 in the seasoning process:
How the process works is when we apply oil evenly on the surface and heat it to its smoke point, the fatty acids in the oil break down (become oxidized) and bond with the metal to form a protective layer. This entire process is called polymerization, and it’s what creates the seasoning on your pan. Think of it like armour for your skillet — every layer of oil you heat turns into a hard, protective shell that fights rust and makes your 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 the temperature at which you typically cook. 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:
Always use 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. They didn’t have the means to just extract and refine grapeseed oil themselves. These days, we’ve got shelves full of options but that doesn’t mean you 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 too
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 I believe it’s important to 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 always like to double-check what the pros 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
Notice how even the biggest 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 flavour, availability and affordability, and having a high unsaturated fat content. Avocado oil meets all these criteria (I’ve seasoned everything from tiny skillets to Dutch ovens with it, and it’s never let me down). It also has the highest smoke point (between 480 and 500 degrees) for any cooking oil which is ideal for any kind of cooking, and it’s reasonably priced on platforms like Amazon and Walmart ($8 for 48 ounces). It also has a high amount of unsaturated fats, is neutral in flavour, and what I like most about it is its numerous health benefits, making it an excellent multipurpose oil for me.
Grapeseed oil:
Now let’s talk about the top-recommended oil by manufacturers. Grapeseed oil is also a great option and has long been considered the best oil for seasoning by food scientists. Many manufacturers who provide their own seasoning oils also include it in their formulations. However, in terms of smoke point (420 degrees) and unsaturated fats, avocado oil is superior. Still, it’s hard to argue with the results. If you’re re-seasoning often or just starting out, grapeseed oil is a safe bet.
Both oils are neutral in flavour and affordable (find it on amazon for 5$ 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, but I don’t think that’s the case. 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 degrees), 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 you’ll see people either love it or swear it off completely. I fall somewhere in between — great for restorations, not my daily go-to.
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 degrees). If you want to use olive oil for cast iron seasoning, look for its refined version (with a smoke point of 465 degrees). 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, thanks to technological advancements, 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 degrees 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 degrees) 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 the 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.
