Best Oil For Seasoning Cast-Iron: Pros & Cons of 9 Oil Options

With dozens of good-quality cooking oils to choose from, picking oil to season your cast-iron can be a tough decision. Here's our guide to all things seasoning oil so you can learn the pros and cons of each oil type and start building a beautiful season on your favorite cast-iron pieces. 

What is seasoning?

Seasoning cast-iron refers to applying a thin layer of cooking oil to its surface to fill the tiny pores that are naturally a part of any cast-iron pan, pot, or skillet. 

If you're at all familiar with the material, you may have heard mention of seasoning cast-iron. Unlike non-stick coated and steel pans, a cast-iron pan needs seasoning before you use it. Otherwise, you'll find it impossible to lift any food off of its surface. 

Some cast-iron cookware comes pre-seasoned, which is a handy feature. You can still season them again to promote the coating's longevity and durability, but it's completely optional. 

For those that come unseasoned, you'll want to do it yourself at home before you even think of using your cast-iron pan. 

Why do you need to season your cast-iron cookware? 

• Seasoning helps to build a strong, non-stick coating that keeps your food moving easily around your pan.
• The smooth iron surface allows you to use less cooking fats and oils, making your meals lower calorie.
• A good seasoning makes foods taste better, as the seasoning absorbs and imparts some deliciously complex flavors from the foods you cook in your cast-iron cookware. 

Benefits of Cast-Iron Cooking

Though it requires an initial seasoning which can be a bit more work, our cast-iron tools are our go-to for cooking almost every meal we make. Here's why:

• It's tough as nails. Your cast-iron pieces are so durable that they'll likely outlive you and your kids, too, if taken care of properly. 
• It retains heat well. While cast-iron takes a while to heat, it has the potential to get to very high temperatures and stays smoking hot for a long time. 
• It's inexpensive. Most cast-iron pieces are of outstanding quality, like this cast iron skillet set, and are still very reasonably priced at $25-$30 per pan. 
• It increases iron intake. Though the levels are low, a tiny bit of iron absorbs into the foods we cook in cast-iron, which helps boost daily intake levels of this essential micronutrient. 

Ultimate Guide to Cast-Iron Seasoning Oils: Pros and Cons

#1: Flaxseed Oil: The Alleged Best Oil to Season Cast-Iron?

For the last decade or so, word on the street is that flaxseed oil cast-iron seasoning is the very best gold-standard from a scientific perspective. While we don't think it's the bad choice, with its low smoke point, but we're not convinced that flaxseed oil is the very best cast-iron oil, either. 

Pros

• According to some, the polymerization of fats from using flaxseed oil leaves your cast-iron surfaces harder, smoother, and more even than vegetable oils, which soften the pans and make them more prone to scratching and wear. 

Cons

• It's expensive, at around $1 per ounce, and goes rancid quickly.
• It has a low smoke point at 225°F and doesn't withstand the seasoning process's high heat well.
• Some people find their flaxseed seasoning gets brittle and flakes off.

#2: Grapeseed Oil - An All-Around Winner

While this oil might not get the same hype as flaxseed, grapeseed oil is our personal #1 when it comes to choosing your very best oil for cast-iron seasoning. It tastes good with most flavors and boasts a much higher smoke point. 

Pros

• The grapeseed oil smoke point sits at 420°F so that it won't burn during the seasoning process. 
• Mild flavors blend well with almost any dish you cook.
• Oil is relatively inexpensive.

Cons

• Beware of cold-pressed and virgin varieties, which have a much lower smoke point and aren't suitable for use as cast-iron seasoning oil.

#3: Canola Oil - Cheap and Gets the Job Done

Canola oil is dirt-cheap to buy and is handy in plenty of recipes, so you likely already have a bottle stashed in your pantry. While canola will get the job done, its results aren't as good for seasoning cast-iron. Flaxseed oil and grapeseed oil both get you better results, but you'll pay a premium for them, too. 

Pros

• Very inexpensive.
• A neutral flavor that won't compete with any foods you cook.
• The canola oil smoke point is relatively high, at 400°F it's more than enough to take on the high heat of seasoning.

Cons

• The first seasoning tends to be weak and create a mottled, bumpy surface. 
• Isn't as non-stick as other options, and the seasoning may break down more quickly than others. 

#4: Coconut Oil - Won't Harden As Well As the Others

We can see why seasoning cast-iron with coconut oil might seem like a great idea, but there are plenty of better oil options on the market. Don't get us wrong, coconut oil is delicious - it's our oil of choice for making cookies and Thai-style curries, and we even use it for body lotion! While the health benefits of virgin coconut oil are undeniable, it's not a great option to season cast-iron with coconut oil because of its saturated fat content. 

Pros 

• Tastes delicious, with a distinctive coconut flavor. 
• Refined oil has a smoke point of 450°F, making it a very high smoke point oil.

Cons

• Expensive
• High saturated fat content lowers the polymerization required in the seasoning process - the seasoning won't harden well. 
• Virgin oil has a lower smoke point of 350°F.
• Strong coconut taste may impact some dishes negatively.

#5: Peanut Oil - Tastes Too, Well, Peanut-y

Peanut oil is prevalent for stir-frying and in Asian cooking, but we don't think it makes the best seasoning for cast iron, as it has a powerful peanut flavor that doesn't always blend well with every meal you cook. 

Pros

• It's one of the highest smoke point oil options, at 450°F.
• Relatively inexpensive compared to some other oil options. 

Cons

• Strong peanut flavor can negatively impact the taste of some dishes. 

#6: Vegetable Oil - Cheap But Less Durable

Vegetable oil is almost identical to canola oil, and you can usually use the two interchangeably. This means that like canola oil, using vegetable oil for seasoning your cast-iron is a cheap option but won't give you the best results. 

Pros

• The vegetable oil smoke point is relatively high at 400 - 450°F. 
• The very light taste won't compete with anything you cook in it. 

Cons

• The seasoning will be very weak at first and require more seasoning sessions than a better oil.
• The non-stick qualities aren't as strong as other options and will break down more quickly, too. 

#7: Sunflower Oil - Inexpensive and So-So Quality Seasoning

Many vegetable oils contain sunflower oil in their blend, making results very similar to canola or vegetable blends. 

Pros

• The sunflower oil smoke point is the same as vegetable blends, topping out at 450°F. 
• The very light taste won't compete with anything you cook in it. 

Cons

• The seasoning will be very weak at first and require more seasoning sessions than a better oil.
• The non-stick qualities aren't as strong as other options and will break down more quickly, too. 

#8: Avocado Oil - A Hardened Coat of (Expensive) Armor

Avocado oil, much like the fruit it comes from, is full of heart-healthy unsaturated fats; but should we use avocado oil for seasoning cast-iron? We think so! The polymerization of the fats in avocado oil will give you a solid and durable seasoning on all your favorite pans. The one drawback to seasoning cast-iron with avocado oil is its price. 

Pros

• High levels of unsaturated fats help to polymerize and oxidize, resulting in a very tough coat of seasoning on your cast-iron. 
• It has an incredibly high smoke point at 520°F - that's one hot oil!
• It has a relatively long shelf-life and doesn't go rancid quickly.

Cons

• It is more expensive than other cooking oil options, which makes sense if you look at the price of an avocado in America. 

#9: Olive Oil - Stay Far, Far Away

One thing you should never, ever attempt is seasoning a cast-iron skillet with olive oil. Olive oil has many health benefits when enjoyed uncooked or in low-heat cooking. With its exceptionally low smoke point, trying to use olive oil to season cast-iron the traditional way will end with burning carcinogens floating into the air. 

While you can try to season cast-iron with olive oil by doing more seasoning sessions at a lower temperature, it seems labor intensive with less predictable results.

Pros

• Relatively inexpensive
• It has a soft and delicious flavor that won't compete with most foods.

Cons

• The lower smoke point at 375°F that can release harmful chemicals as it burns.

Best Oil to Season a Cast-Iron Skillet - FAQ

What is the best oil for cast-iron cooking?

Once your pan is seasoned, you'll want to drizzle in a small amount of oil as you cook, just as you would with any other pan. The best oil for the job largely depends on what you're making and which tastes you prefer. 

One thing to keep in mind is the smoke point - if you're cooking over high-heat, a low smoke point oil will burn and release potentially harmful carcinogens. For low-heat cooking, you have a more comprehensive range of safe options. 

How often should I season cast-iron?

Once you establish the initial coat of seasoning on your cast-iron cookware, you can start cooking with relative ease - don't worry about the seasoning too much. With proper use, seasoning cast-iron, again and again, should be unnecessary, as the seasoning will naturally build as you cook. 

Re-season a cast-iron skillet or pan only if food begins to stick to it easily, it develops rust spots, or loses its shiny, smooth patina.

How many times should I season my cast-iron skillet?

You should repeat the initial seasoning process three or four times - while the initial layer is just your jumping-off point and your season will improve and strengthen over time, food will stick to the pan too easily with just a single coat of seasoning. 

Once you get past the initial process, you'll know how to season cast iron, and re-seasoning anything from pans to pie irons will be much easier. When you re-season, once is enough.

The frequency of re-seasoning depends on how often you use your utensils, and it may wary from one piece of cookware to another. The more you use it, the less maintenance it needs. If you have a trusty Dutch oven for weekly stews and roasts, the oils used in cooking will keep the non-stick layer on for longer. But a pie iron that's been sitting aside throughout the cold season may need some more serious re-seasoning once you get back to it. Ultimately, it's time to re-season when the food starts sticking to the surface.

What temperature do I use to season my cast-iron skillet?

Your oil needs to hit high heat to fuse to your pan and provide a smooth, non-stick coating. 

Place your oiled cast-iron pan into an oven and heat to 450°F, then leave it there for 30 minutes. Turn off the heat and leave your pan in the oven to cool to achieve a better season and avoid touching the burning hot cast-iron. 

Verdict: Which Oil is Best to Season Your Cast-Iron?

After weighing the pros and cons, our personal top choice is a two-way tie: grapeseed oil and avocado both make the best cast-iron seasoning options. 

While you can't go wrong, either way, our financial sense pushes us a little further toward the grapeseed oil because a bottle costs a little bit less than avocado oil. 

Whichever oil you choose, you'll want to head over and read how to season cast iron properly so you can start using your new cast-iron skillet ASAP!