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Comment by giraffe_lady | Hacker News Reader

When you add the oil doesn't matter for cooking as long as you let the total pan-oil system get up to temp before you add the food. Leidenfrost is used as a quick indicator that the empty pan is the right temp, but oil doesn't do a leidenfrost effect.

The advice to pre-heat the pan first is because if you forget an empty pan on the stove you get a hot pan, if you forget an oiled pan on the stove you get a grease fire.

Also try out carbon steel for a more nonstick type situation. Stainless is best when you want some sticking, like for building a fond for a pan sauce. Carbon naturally seasons similarly to cast iron, but much lower maintenance because you can wash it however you want and essentially rebuild the seasoning from scratch for each use.

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> When you add the oil doesn't matter for cooking as long as you let the total pan-oil system get up to temp before you add the food. Leidenfrost is used as a quick indicator that the empty pan is the right temp, but oil doesn't do a leidenfrost effect.

1. It matters because oils oxidize rapidly (and can begin breaking down) in the presence of high heat. You want the oil to be relatively fresh while using it to cook. This is less of an issue with highly refined oils, but a problem with most natural oils.

2. Oil isn’t affected by leidenfrost, but the food you are cooking is. This effect prevents the food from falling below the oil layer and sticking/burning to the pan when the oil is moving due to water boiling off. When water molecules in the food come in contact with the surface of the pan below the oil, leidenfrost forces them to float back above with the food and allow oil to flow back into the space.

Moving food as you cook it helps with this as well. If you cook at the wrong temperature without this effect, oil gets displaced from below the food and it sticks. This is especially difficult with very wet foods with minimal structure like eggs.

Sure leidenfrost is a fine model to use when thinking about food sticking to your pan and preventing it etc. It still has nothing to do with when you add the oil though.

No cooking oil is going to appreciably oxidize in the 70 seconds it takes to heat a pan. I cooked at very high levels for many years, I have seen a cook get fired on the spot for handling a pan incorrectly, no one cares about whatever oxidation is happening during preheating. The advice to add oil to the hot pan is so you don't forget and overheat the oil, or start a fire.

It takes much longer than 70 seconds to heat up a 12 inch stainless steel or carbon steel skillet on a home burner to a point where it can be used to fry an egg or sear a chicken thigh, both of which are things a home cook may do with some frequency.

Am I missing something? Putting oil into a hot pan causes it to spit and that is how to get an oil fire.

Oil by itself won't spatter, that's caused by water cooking off. Butter will spit because it's got water in it. Reused fry oil and things like that can also, because they tend to have some fried food bits holding moisture still in there. But just pure oil no.

Hot as in 212-350F, not 450F+

Side note, many people cook with way too much heat.

It depends on what temperature you mean by "hot" and which oil you're referring to. If you're in the band of temperatures in which water produces the leidenfrost effect you are at a good temperature to add oil, if it's too hot you'll know and if it's too cool you'll know if you test your pan with a drop of water before you add the oil and begin cooking.

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