The One Thing You Shouldn't Cook In A Cast Iron Skillet

The holy grail of kitchen equipment: the cast iron skillet.

This kind of skillet is made of nearly unbreakable iron; drop it on the floor, bop it over someone's head, and you will find it can take (and cause) some serious damage. Prone to scratches, rust, crust and discoloration, the cast iron skillet will still, somehow, outlast you.

But, you have to take care of these bad boys because you will be sorry if you cook tomatoes (or any highly acidic foods, including vinegar and wine) on these gleaming iron pans. 

Tomatoes are fairly acidic, so when heated, they will tend to react to the skillet's metal. Trace amounts of iron molecules can loosen and leach into your delicious meal leaving guests wondering why they have the taste of licking a penny stuck to their palates. Although this hasn't been found to be entirely harmful, the result is a little less savory and more, well, metallic-tasting, obviously.

But, if this rule has long been broken, rest easy! As long as you follow the sacred cleaning rule of iron skillets, you should be fine. As many cast iron skillet owners understand, the first rule of cleaning a skillet is this: you don't.

Instead, you give it a nice wipe down, scrub with salt if you must, then season it; usually olive oil or any kind of animal fat will do. But, do keep in mind that over time acids will eat away at this protective layer, eventually rendering this holy grail non-stick iron skillet unusable, and in need of re-seasoning.

America's Test Kitchen tested the reaches of this "no acids" rule and found that it applies only to a certain extent. They found that the metallic taste was noticed after 30 minutes of cooking highly acidic foods in a cast iron skillet.

So go ahead and add a splash of lemon to finish off a pan-fried chicken. No sweat. In fact, you really don't have to sweat it too much at all, as long as you avoid using your cast iron for slow-cooked, tomato-based meals and the like.

But if you simply must cook a ragu in the skillet, or use cooking wine for sauteeing, just make sure not to keep it in the heat for too long!