Why?
My best domestic frying pan is a small steel thing i got from tchibo. Food never really sticks apart from some outlyers because of the way i cook. Cleaning it a doddle, minimal soaking and clean with one of those wire pads. Still good as new on the inside.
So what's the problem with steel?
Don't confuse steel with stainless steel. The two are not the same. Stainless steel used in kitchenware contains about 18% chrome and 8% nickel.
Steel contains no chrome or nickel, only a bit of carbon and in the case of special steels, such as tool steel, some vanadium or cobalt etc.
For the purpose of my statement, that stainless steel is horrible for anything other than boiling (i.e. frying), the issue is the poor heat conductivity of stainless steel. When your frying pan material doesn't conduct heat all that well, you get hot spots. If you cook on a gas ring, then the heat inside the pan is concentrated where the gas ring burns. Your eggs burn in the middle but doesn't cook on the outer edges. This is evident if you examine an older pan or have burnt a pan, you'll see the ring where the heat was concentrated. Then, if you burn something in a stainless steel pan (like proper burn it until the kitchen stinks), the pan is permanently stained. This is because carbon from your food has now ingressed into the steel and formed other compounds such as , perhaps, cementite (the same stuff that messes up car brake discs when overheated and make them feel as if they're warped).
On the other hand, if you use a nice thick aluminium pan, the heat distributes evenly and it never stains when burnt on. Any burns remain superficially on the surface and can be scoured off.
How poor a conductor is stainless steel? On a scale of 1 to 400, where 400 is the best, stainless steel has a score of 15. Aluminium has a score of 237 and copper, 399. Copper is great for cooking and all sorts of other applications where heat conductivity is required. Someone mentioned fancy pantsy titanium pans. Well, Ti only scores 17. It is totally inappropriate for cookware.
Carbon steel is much better than stainless, scoring 43. But, as you can see, it pales in comparison to aluminium. Just as a silly comparison, glass has a score of less than 1, meaning that a glass frying pan is not a good idea.
Evenness of heat distribution in a pan is thus a function of the material (alu good, stainless bad), but also a function of the material thickness. If the pan is a bit thicker (which is not a problem with aluminium because it is so light), heat distribution is excellent.
However, cooking is not only about heat distribution. It is also about thermal mass. This refers to how much heat the pan can store. The more it can store, the less it will cook down when you chuck a cold steak onto it. That's why heavy cast iron pans are preferred for searing steak. You heat the hell out of the pan and lay down your steak. It will sear and keep on searing, because there's such a lot of heat stored in that heavy pan.
The conductivity of stainless steel and aluminium is easily experimented with in the kitchen. Next time you want to defrost something, put it in your stainless steel kitchen sink. After ten minutes, lift it up and notice how it has now frozen to the sink. Feel the cold spot directly under the frozen item and notice how the temperature just 10 cm further away, is almost ambient.
Now take that same frozen item and put it on an aluminium baking tray. It will never freeze onto the tray, because the heat (cold) is distributed away from the centre. Also, the entire sheet is ice cold. Defrosting food on an aluminium tray is several times faster than trying to defrost it in open air or in a kitchen sink or even in water. The aluminium tray is an excellent heat exchanger. Even if your frozen item isn't perfectly flat, the few contact points will quickly defrost, allowing the item to make better contact over a larger surface area and defrost quicker and quicker.
Stirring your coffee with a stainless steel spoon is perfectly safe. Had that spoon been aluminium or copper, you would burn your fingers each time you stir.
In days gone past, some premium cookware would feature copper bottoms. Usually an outer layer of copper, sandwiched onto a thick layer of alumium, sandwiched onto the stainless steel pot or pan's bottom. There was good reason for that.
There's beautiful science all around you, even in your kitchen. Observe, think, ask and enjoy.
