The Best Oils for Seasoning Cast Iron: A Complete Guide
Update (June 8, 2025): This post has been revised to include additional Crisco facts, peanut oil as a seasoning option for cast iron, and updates to the Final Thoughts section. If you've read this before, be sure to check out these new insights!
Seasoning cast iron is the key to a durable, nonstick surface that makes cooking easier and prevents rust. Choosing the right oil is essential for a strong, long-lasting seasoning. This guide breaks down the top 10 oils, analyzing their effectiveness, polymerization strength, longevity, and potential drawbacks.
Why Seasoning Matters
Seasoning a cast iron pan involves applying a thin layer of oil and heating it until it polymerizes, forming a hard coating that protects the pan. The best oils for seasoning have high smoke points, rich unsaturated fat content, and excellent polymerization properties.
1. Grapeseed Oil — The Top Choice
Grapeseed oil ranks as the best option for seasoning cast iron. It has a high smoke point of around 420°F, allowing it to create a slick and durable seasoning.
Key Benefits:
Forms an excellent polymerized layer that resists flaking
Neutral flavor with no sticky residue
Affordable and widely available
High in polyunsaturated fats that strengthen the seasoning
Potential Drawbacks:
Moderate risk of going rancid over time
2. Flaxseed Oil — The Hardest Seasoning Layer
Flaxseed oil is known for creating an exceptionally hard seasoning due to its high omega-3 fatty acid content. This oil polymerizes into a glossy, glass-like layer, which helps maintain a smooth cooking surface.
Key Benefits:
Creates a highly durable seasoning layer
Long-lasting but slightly brittle
Works well for initial seasoning applications
Potential Drawbacks:
Expensive compared to other oils
Highly prone to rancidity if not stored properly
3. Canola Oil — A Budget-Friendly Alternative
Canola oil provides solid polymerization with a smoke point of 400°F. It is an inexpensive and effective option for seasoning, widely used by home cooks.
Key Benefits:
Affordable and easily accessible
Neutral taste and smooth seasoning layer
High in monounsaturated fats, aiding polymerization
Potential Drawbacks:
Can create a slightly sticky coating if applied too thickly
4. Vegetable Oil — A Reliable Choice
Vegetable oil functions similarly to canola oil, delivering decent seasoning with a high smoke point. It is ideal for everyday maintenance of cast iron pans.
Key Benefits:
Cheap and widely available
Creates a smooth seasoning layer
Good polymerization properties
Potential Drawbacks:
May leave residue and require additional layers
5. Avocado Oil — Long-Lasting Durability
Avocado oil has an exceptionally high smoke point of 520°F, making it ideal for high-heat applications. It forms a strong, lasting seasoning layer and resists breakdown.
Key Benefits:
Superior longevity, requiring fewer re-seasoning sessions
Resistant to oxidation, meaning it lasts longer
High in monounsaturated fats, enhancing polymerization
Potential Drawbacks:
Expensive compared to other oils
6. Sunflower Oil — A Balanced Option
Sunflower oil provides good seasoning results while remaining budget-friendly. With a smoke point of 440°F, it polymerizes well but can degrade faster than grapeseed or flaxseed oil.
Key Benefits:
Affordable and easily accessible
High in polyunsaturated fats for effective polymerization
Potential Drawbacks:
Moderate risk of rancidity, requiring careful storage
7. Crisco (Vegetable Shortening) — Easy Application
Crisco is a solid fat that simplifies the seasoning process. While it does create a usable seasoning layer, it is less effective than liquid oils.
Key Benefits:
Easy to apply and spread evenly
Affordable and widely available
Potential Drawbacks:
Shorter longevity, requiring frequent re-seasoning
Can leave a sticky residue
Additional Crisco Facts Direct from the Source
You’ll find a wide range of smoke points online for Crisco Vegetable Shortening so I reached out to the Consumer Affairs Office at B&G Foods. Here’s their response:
“The smoke point of Crisco depends on the type you're using:
1. Crisco All-Vegetable Shortening
Smoke point: ~360°F to 370°F (182°C to 188°C)
2. Crisco Vegetable Oil (blended soybean oil)
Smoke point: ~400°F to 450°F (204°C to 232°C)
3. Crisco Canola Oil
Smoke point: ~400°F (204°C)
These are general ranges, as the actual smoke point can vary slightly based on batch and freshness. When heating fats like Crisco, it's best to stay below the smoke point to avoid off-flavors and breakdown of the oil.”
8. Lard — A Traditional Option
Lard has been used for generations to season cast iron. It forms a smooth, effective coating, though it has a higher risk of going rancid over time.
Key Benefits:
Creates an excellent cooking surface
Ideal for traditional seasoning methods
Potential Drawbacks:
Can spoil faster than plant-based oils
Adds a distinct flavor
9. Bacon Fat — Rich Flavor and Smooth Coating
Bacon fat works similarly to lard, creating a smooth seasoning with added depth of flavor. It is ideal for frequent cooking, as it enhances the pan’s patina over time.
Key Benefits:
Free if you cook bacon regularly
Forms a solid seasoning layer
Potential Drawbacks:
High risk of rancidity, requiring careful storage
Leaves a strong taste in the pan
10. Coconut Oil — A Lesser Choice
Coconut oil forms a seasoning layer but lacks durability due to its high saturated fat content. It is less resistant to heat degradation, requiring frequent reapplication.
Key Benefits:
Natural and widely available
Easy to apply
Potential Drawbacks:
Short-lived seasoning that breaks down quickly
Can leave a noticeable coconut flavor
11. Peanut Oil — A Stable and Versatile Option
Peanut oil is a solid choice for seasoning cast iron due to its high smoke point and stability. It creates a durable seasoning layer that resists breakdown over time.
Key Benefits:
High smoke point (~450°F), making it suitable for seasoning.
Forms a stable, protective coating that enhances nonstick properties.
Neutral flavor that won’t overpower food.
Potential Drawbacks:
Not allergen-friendly—those with peanut allergies should avoid using it.
Contains a high amount of omega-6 fats, which may degrade faster than some other oils.
Final Thoughts
Ultimately, the best oil for seasoning your cast iron is the one that works best for you and fits your cooking style. Many seasoned cast iron enthusiasts swear by good ol’ fashioned Crisco shortening, while others prefer oils with strong polymerization properties like grapeseed or flaxseed oil. If you’re new to cooking with cast iron and seeking guidance, keep in mind that the ideal oil should offer excellent polymerization strength, long-lasting durability, and minimal flavor impact. Experimenting with different options will help you find the perfect seasoning method for your cookware.
Top Choices:
Grapeseed oil provides exceptional durability with an excellent nonstick surface.
Flaxseed oil creates the hardest coating but needs careful storage.
Avocado oil offers long-lasting seasoning but is more expensive.
Budget-Friendly Alternatives:
Canola oil and vegetable oil offer solid seasoning results at low cost.
Sunflower oil works well but requires careful storage.
Traditional Options:
Lard and bacon fat add unique flavors but have a higher risk of spoilage.
For long-term cast iron maintenance, grapeseed oil and flaxseed oil are top recommendations. Proper seasoning and regular upkeep will ensure your cast iron cookware performs beautifully for years to come.