You probably grew up hearing about the magic of cast iron skillets. They’re nearly indestructible, heat evenly, and develop that perfect nonstick surface over time. There’s one thing people get wrong about caring for these kitchen heirlooms, though, and it’s a mistake I see constantly.
The culprit? Olive oil.
I know what you’re thinking: olive oil is in every kitchen, right there on the counter, and it feels like a safe, versatile choice. Turns out, when it comes to cast iron pans, it’s probably the worst option you could reach for. Let’s break down exactly why experts cringe when they hear about people seasoning their pans with olive oil.
The Smoke Point Problem Is Real
Olive oil has a smoke point somewhere between 325 and 375 degrees Fahrenheit. That’s honestly pretty low compared to what you need for proper cast iron care. When you’re seasoning cast iron, you’re aiming to heat the pan well above the oil’s smoke point to trigger a chemical process called polymerization. Oils or fats need to be heated at a high enough temperature to change from a wet liquid into a slick, hardened surface through polymerization.
Here’s the thing. If your oil smokes at such a low temperature, it starts breaking down before it can properly bond with the iron. Once you start cooking with a pan seasoned with olive oil and heat the skillet higher than its smoke point, the oil will start to degrade, wearing off faster than other types of oil and leaving your cast iron unprotected. You end up with sticky residue instead of that glassy, smooth finish you’re after.
It Creates a Sticky, Gummy Mess
Picture this scenario. You carefully coat your pan in olive oil, bake it in the oven, and pull it out expecting a beautiful black patina. Instead, the surface feels tacky to the touch. Sound familiar? When the seasoning doesn’t stick properly to the surface and you heat it above its smoking point, the seasoning begins to degrade and the layer of oil begins to wear off, making your pan sticky.
Olive oil has a relatively low smoke point and can break down at high temperatures, leading to undesirable flavors and stickiness. This isn’t just annoying from a texture standpoint. That gummy layer doesn’t protect the iron underneath, meaning your pan is vulnerable to rust and food will stick like crazy during cooking. Nobody wants scrambled eggs welded to their skillet.
Extra Virgin Is Even Worse
If you thought regular olive oil was problematic, extra virgin is on a whole different level. Extra virgin olive oil, with its lower smoke point and higher content of impurities, is the least suitable type of olive oil for seasoning cast iron, as its relatively low smoke point makes it more prone to creating a sticky residue when heated to the temperatures required for proper polymerization.
The impurities and free fatty acids that give extra virgin olive oil its rich flavor are exactly what cause problems for cast iron. These compounds just don’t polymerize well. They’re wonderful for salad dressings or finishing dishes, don’t get me wrong. They’re just terrible for building that protective seasoning layer on your cookware. Olive oil is great for cooking, but it has a much lower smoke point than many other types of oil, so it’s not recommended for seasoning cast iron.
The Science Behind Polymerization Matters
Let’s talk chemistry for a second, because understanding this makes everything click into place. Seasoning isn’t merely coating your cast iron with oil; it’s a chemical process called polymerization that involves heating oil to a point where it breaks down and bonds with the iron, creating a hard, smooth, and non-stick layer that transforms into a plastic-like coating.
Drying oils, which produce the hardest polymers, are characterized by high levels of polyunsaturated fatty acids, especially the omega-3 fatty acid ALA. Olive oil is primarily monounsaturated fat, not polyunsaturated. This fatty acid profile means it just doesn’t form those strong, durable polymer chains that make great seasoning. The molecular structure simply isn’t ideal for the job.
Better Oil Options That Actually Work
So what should you use instead? Good question. Amongst all the oils used for seasoning cast iron, grape seed tops the list, as it has a high smoke point, low saturated fat content, and is extremely durable, binding amazingly with the iron’s surface to produce a long-lasting, hard film with its strength really in its high smoke point of 420 degrees Fahrenheit.
Avocado oil is another powerhouse choice. Avocado oil has one of the highest smoke points, around 520 degrees Fahrenheit, of all cooking oils, making it an excellent choice for seasoning cast iron, and it contains a high percentage of monounsaturated fats with a neutral flavor. Popular cast iron brand Lodge recommends vegetable oil, canola oil, or even melted shortening for seasoning. These options have the high smoke points and appropriate fat compositions to create truly durable seasoning layers.
Even Cooking With It Can Be Problematic
Okay, so you shouldn’t season your pan with olive oil. What about just cooking with it? Honestly, that’s questionable too. With its low smoke point, olive oil can easily burn, leaving behind a residue that can be tough to clean off your cast iron pan, and it’s best saved for stovetop cooking at lower temperatures.
If you’re searing a steak or getting a good char on vegetables, you’re going to exceed olive oil’s smoke point almost immediately. That means burnt oil flavors in your food and another layer of problematic residue on your pan. When cooking in cast iron, you should add a little oil to the pan before adding your food to help ensure the food doesn’t stick and to help build layers of seasoning, and you can generally use whatever oil you prefer, as long as the cooking temperature is below the smoke point of the oil. For high-heat cooking, olive oil just doesn’t make the cut.
Your Seasoning Degrades Faster
Even if you somehow manage to get olive oil to season your pan initially, the problems don’t stop there. Seasoning with olive oil may require more frequent upkeep, especially if you often cook at high temperatures, which is why many experts recommend comparing olive oil to other seasoning oils to find the best fit for your needs.
Think about what happens every time you cook. The heat breaks down that weak olive oil seasoning bit by bit. You’ll find yourself constantly needing to reseason the pan, stripping and starting over, dealing with rust spots. Meanwhile, someone who used grapeseed or canola oil from the start is happily cooking away with minimal maintenance. It’s frustrating and completely avoidable.
Refined Versus Unrefined Doesn’t Fix It
Some people think switching to refined olive oil or “light” olive oil solves the problem. Light or refined olive oil can handle up to 465 degrees Fahrenheit, and because of its higher smoke point and milder flavor, light olive oil is often the better choice for seasoning cast iron. That’s technically true compared to extra virgin, but it still doesn’t make it a great option overall.
While olive oil can work for seasoning over time, its stronger flavor and lower smoke point may not deliver the neutral, long-lasting coating that some other oils provide. You’re still dealing with suboptimal polymerization and faster degradation compared to the alternatives. Why settle for “better than the worst option” when you could just use the right oil from the start?
Professional Cookware Companies Avoid It
It’s telling what the experts actually use. Lodge was the first brand to begin seasoning cast iron cookware in the foundry, spraying a thin layer of soy-based vegetable oil onto their cast iron and carbon steel pots and pans and then baking the cookware in a large oven, and based on availability, affordability, effectiveness, and having a high smoke point, Lodge recommends vegetable oil, melted shortening, or canola oil.
Notice what’s missing from that list? Olive oil. The people who literally manufacture cast iron for a living, who’ve spent over a century perfecting the seasoning process, don’t touch the stuff. That should tell you everything you need to know. They use vegetable oils with high smoke points and polyunsaturated fats because those are what create durable, long-lasting seasoning.
