What causes sticking and what can I do to reduce food sticking to my cast-iron skillet?

Question

I enjoy using my cast-iron skillet, but how can I minimize the amount of food that sticks to it while cooking? I apply oil after cleaning, and for the most part, I only clean it with hot water and a rag.

For the most part, breads (pancakes, sandwiches) and meats do fine, but I have particular trouble with potatoes and fried eggs.

What causes sticking and what can I do to minimize the it?

Asked by Abe

Answer

The first rule to keeping food from sticking to cast-iron is to keep it well primed - it sounds like you're doing that already. Beyond that, read these tips for cooking with stainless steel - they'll also apply to cast iron.

To summarize:

• Food sticks when chemical bonds form between the food molecules and the metal.
• Very hot oil helps to reduce sticking by instantly and continuously heating the food until it's surrounded by a layer of steam from its natural moisture content boiling. Let the oil get nice and hot before adding food.
• Very hot oil also binds with the pan, so food can't. This is the principle behind priming the pan in the first place.

I have some theories regarding particular problem foods:

• Most of the molecular bonding occurs from proteins. Egg whites are mostly protein.
• Frying potatoes creates surfactants in the oil, which cause oil and water to mix. This reduces the effect of the protective layer of steam. (Some people save and re-use cooking oil -- though it can impart a delicious flavor to later meals, it will also build up surfactants if the same oil is used too many times.)
• Also, keep in mind that acidic foods like tomatoes will break down the protective patina and may make foods stick more readily.

Answered by Josh

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