A cast iron skillet is an integral tool in a home kitchen, but there are do’s and don’ts that must be respected.
If you own a cast iron skillet, you should know that it first needs to be seasoned. Any by seasoning, we mean giving it a good protective coating of oil. You’ve probably also heard that you should never wash it with soap. And you should never leave it out to air dry. (Dry it on the stove over low heat.)
There’s one more thing you should know: it’s a bad idea to cook tomato sauce, or any other super acidic food, in cast iron. Acid reacts with the metal and can cause some of the iron to leach out into your food. While the potential health risk is extremely low, it can make the food taste metallic. And it can ruin the seasoning on your skillet.
Of course, there is a little leeway, just like there is with soap on the cast iron. (Because, yes, in a pinch you can wash your cast iron with soap, you will not destroy it.) If you take some precautions, you don’t need to be too worried about ruining your favorite skillet.
For one, make sure your skillet is well-seasoned. A well-seasoned skillet can withstand the acid in most foods. Seasoning can stop the acid from reacting with the iron. If you’re cooking with a poorly-seasoned skillet, you might want to reconsider.
Secondly, if you’re quickly cooking tomato sauce in the skillet, there’s not much chance for iron to be leached out. America’s Test Kitchen found that only after cooking very acidic foods for 30 minutes in a cast iron skillet there was a noticeable metallic flavor. So just make sure you’re not making any slow-cooked tomato sauces in your cast iron.