Cast Iron and Soap: Debunking the Age-Old Myth

If you’re a fan of cast iron cooking, you have probably heard the phrase “no soap on cast iron” countless times. This mantra has been repeated by many cooks, chefs, and cast iron enthusiasts for generations. But is it really true? Can soap actually damage your cast iron’s seasoning? Or is it just a myth that needs to be debunked?

Read on as we explore the history, science, and the opinions of different cast iron brands on cast iron and soap.

A Brief History of the “Cast Iron and Soap” Dilemma

To understand why some people are wary of using soap on cast iron, we need to go back in time and learn about lye. Lye is a chemical compound made from wood ash and water. It has many uses, such as making soap, cleaning, and curing food. However, lye is also highly caustic, meaning it can burn or corrode organic materials.

Lye has been used for centuries to make soap, especially in the old days when people had to make their own from animal fat and lye. However, lye-based soaps were not very friendly to cast iron cookware. Since lye can dissolve oil and grease, it can also strip away the seasoning on cast iron pans.

As a refresher, seasoning is the layer of polymerized oil that forms on the surface of cast iron when heated and treated with oil. This layer protects the metal from rusting and gives it a non-stick quality.

Lye is so effective at removing seasoning that some cast iron collectors use lye baths to restore old, rusty cast iron pieces. They soak the pans in a water and lye solution for several days or weeks until all the rust and old seasoning are gone. Then, they rinse, dry, and re-season the cookware.

However, modern soaps are not the same as lye-based soaps. Today’s mass-produced soaps don’t contain lye. They also have other ingredients that make them less harsh and more gentle on the skin and other surfaces. As such, using modern soap or dishwashing liquid on cast iron is not as risky as utilizing lye-based soap.

Can Soap Damage Your Cast Iron’s Seasoning?

The short answer is: no, not really. While soap can and will remove oil from your cast iron pan, it will not damage the seasoning layer. That is because the seasoning is no longer oil—it’s already polymerized oil, which means it has undergone a chemical reaction that bonds it to the metal. And soap cannot break this bond easily.

However, there are some caveats to this. First, you should avoid using lye-based soaps on your cast iron, as they are still very harsh and can damage your seasoning. They are still widely used in natural or organic soaps, so be careful when choosing your soap. You can check the ingredients list or look for labels that say “saponified” or “contains sodium hydroxide” (which is another name for lye).

Secondly, you should also avoid using dishwasher detergent on your cast iron. Dishwasher detergent is a special type of soap designed for electric dishwashers. It’s very powerful and can remove grease, food particles, and stains from dishes. However, it can also strip away your seasoning layer if you use it on your cast iron. Thus, you should never put your cast iron in the dishwasher or use dishwasher detergent to clean it.

Where Do Brands Stand in the “Cast Iron and Soap” Fence?

You might wonder what different cast iron brands think about using soap on their products. Do they recommend it or discourage it? Here are some brands and where they stand in this discourse:


Lodge is one of the world’s most popular and well-known cast iron brands. They have been making cast iron cookware since 1896. On the topic of using soap on their products, the company says, “Soap isn’t necessary, but you can use mild dish soap to clean cast iron. The seasoning on Lodge cast iron is fairly resilient and can withstand a little bit of soap, water, and a good scrub with a brush.”

Field Company

Field Company is a relatively new cast iron brand founded in 2016 by two brothers who wanted to revive the tradition of American-made cast iron.

Their position on using soap on their products? “Yes, absolutely! The idea that you can’t use soap to clean your cast iron comes from the days when many soaps contained lye, which damages seasoning. These days, most dish soaps are totally fine for use on your cast iron, and can often help remove sticky oil residues. So soap away!”


Smithey is another new cast iron brand launched in 2015 by a former banker who wanted to create heirloom-quality cast iron cookware. Their position on using soap on their products is simple, “A few drops of dish soap won’t hurt.”

As you can see, most cast iron brands are not opposed to using soap on their products as long as it’s mild and not lye-based. They also emphasize the importance of rinsing, drying, and oiling your cast iron after washing it.

So, To Soap or Not to Soap?

The myth of cast iron and soap being incompatible has been around for a long time, but it’s not based on solid facts. Modern soaps are not as harsh as lye-based and will not harm your cast iron’s seasoning.

However, you should still be careful about the type of soap you use and how you wash your favorite kitchen find. You should also follow the instructions and recommendations of your cast iron brand to ensure the best performance and longevity of your cookware.

Enjoyed this article? If you love cast iron cooking, you will love Cult of Cast Iron! From helpful tips to honest reviews, we’ve got you covered!

Don’t miss out on the fun and join the cast iron community! Scroll through our blog and explore the world of cast iron cooking today!

Leave a Comment