Is Dish Soap Safe on Cast Iron? (4 NEED to Know Items)


One of the most common questions in cast iron care revolves around using soap to clean cast iron. Particularly, if soap will affect or ruin your hard-earned seasoning. Rest assured, we’ve got you covered.

Dish Soap is perfectly safe to use on Cast Iron! Commonly available dish soaps are mild enough that the chances of stripping off your seasoning are slim. However, if your cast iron is new, avoid washing with dish soap right away as it may affect the manufacturers initial seasoning.

While certainly safe to use, read on to learn why soap is safe, why you should use it and the specific time we suggest not using soap on your cast iron. While not necessary after every use, soap can and should become part of your regular cast iron care and maintenance routine.

1. Warnings Against Using Soap on Cast Iron May Be Outdated

Perhaps you’ve heard cast iron purists or long-time cast iron users say “Never use soap on your cast iron!”. While this may have been good advice at some point, the advice is largely outdated and has become more of an old wives’ tale. Why might that be? The overwhelming majority of currently available dish soaps are MUCH milder than soap from the early days of soap making up until the soap of the mid-1900’s.

Early cast iron cooks (those who passed down their cast iron tips and tricks from the mid 1800’s or so) may have tried using homemade or locally made soaps to clean their cast iron. Sometimes these soaps were more abrasive and highly alkaline, often due to having residual amounts of Lye (Sodium Hydroxide) in them.

Lye is a strong alkaline chemical which is used today for industrial strength oven cleaners, degreasers and drain unclogging liquids. As you might imagine, these early homemade or locally made soaps may have easily stripped away cast iron seasoning if there were high amounts of Lye in the soap, thus giving credence to the “Never use soap on your cast iron” advice many of us have likely heard.

2. Modern Dish Soap is Incredibly Gentle

While Lye is incredibly strong and abrasive on its own, it is a foundational ingredient in soap making. When soap is made safely and correctly, there is no residual Lye in the final product after a chemical reaction process called saponification. Due to todays safety standards and streamlined manufacturing practices, the likelihood of coming across abrasive and harmful soap is virtually zero.

As consumer trends have changed and demand for less toxic and more eco-friendly products has grown, it’s likely that you may be using a synthetic soap at home. Synthetic soaps grew in popularity in the 1950’s and are typically made without Lye.

How gentle is today’s dish soap? Many of you may recall Dawn ads and commercials showing baby ducks caught in an oil spill being cleaned with Dawn Soap. Wildlife conservation organizations such as International Bird Rescue have used Dawn Dish soap for 40+ years for its degreasing effectiveness and because its gentle enough to use on animals.

Today, it’s perfectly safe to use a moderate amount of dish soap without having to worry about ruining or affecting your cast iron’s seasoning. Dish soap is more so engineered today to help degrease and help with cleanup with less reliance on harmful chemicals that could be corrosive or damaging.

3. Dish Soap Makes for Easier Cleanup

Now that we know dish soap is safe, we suggest using a small dot of dish soap to clean your cast iron after every use, if possible. While it may be a mental hurdle if you’ve never used soap on your cast iron before, we suggest giving it a try. You may have had grease and fat turn into saturated fat when your cast iron cools or even when rinsing with water. While some cast iron cooks may take the time to reheat their dirty cast iron, wipe and rinse, using dish soap can help cut the grease quickly for easier cleanup and reduce the amount of effort and elbow grease needed to scrub your cast iron clean.

A large majority of commonly available dish soaps contain surfactants, or Surface Active Agents, which help in the cleaning process. A surfactant’s role is to reduce the tension between the solid pan and oil, liquids and other organic matter so that it’s easy to remove any grease or left over food. This is why dish soaps are so effective at cleaning and degreasing and require minimal effort with a sponge or brush after a quick soak.

One of the most common surfactants in dish soap is sodium lauryl sulfate, an organic compound that bonds to oil and grease and suspends it in water in order to easily be wiped or rinsed away. This ingredient is so common, effective and useful that it can be found in products such as Dawn Ultra Liquid Dish Soap as well as in shampoos, toothpaste, facial cleansers and shaving creams.

Although we consider dish soap safe and suggest it for quickly cleaning your cast iron after cooking, there’s one area where dish soap should probably be avoided: when your cast iron is brand new.

4. Using Soap on NEW Cast Iron May Damage or Remove Pre-Seasoned Surface

If you’ve bought a new cast iron pan recently from any major retailer or manufacturer, it’s more than likely that the cast iron was pre-seasoned. This is to say the manufacturer took the time to treat and season the cast iron prior to selling it to you.

While it’s certainly convenient to be able to use your cast iron right away, we don’t suggest using soap on new cast iron and being especially cautious about using abrasive scrubbers during cleanup. If you use your cast iron right out of the box and immediately begin to use dish soap with steel wool, hard bristle brushes, chainmail scrubbers, etc., then you risk agitating the only seasoning layer that currently exists on your cast iron.

We suggest building on to the existing seasoning and avoiding using soap for the first handful of times you use your new cast iron. What will also be helpful in building the seasoning is to cook fatty foods such as bacon or sautéed vegetable or roasted potatoes in butter as these are less likely to stick than proteins or desserts. Again, all of this is out of caution more than anything else as the quality of the pre-seasoning applied by the manufacturer may vary from brand to brand. After all, no cast iron cook has ever said that additional seasoning is a bad thing!

Conclusion

We hope you’ve found this helpful and have eased your fears about using soap on your cast iron cookware. As always, in the even food begins to stick to your cast iron, it’s time to put in some work on seasoning your cast iron.

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