Dark steel pans have been billed as the answer to various baking prayers, and in a few cases they are. But you have to go beyond the conventional wisdom about how to use them.
A number of different kinds of pans are lumped together under the general rubric "dark" (often called "black") steel. In many cases -- in baking pans and sheets that you find in most cookware stores -- the pans are medium-gauge carbon steel with a black coating of some kind.
This coating may be simply sprayed on by the factory after the pan is formed, or it may be applied to the steel in a sort of laminating process. In the latter case, the steel and its layer of black coating are then formed as if it were a single layer.
In either case the coating can be worn away if you're not careful. A sharp knife will scratch it, scouring will damage it and eventually wear it off altogether. What you're scratching away is often a synthetic material, similar to Teflon, that manufacturers claim is as "easy-release" a surface as its trademarked cousin.
Another kind of dark steel is plain, true, rustable carbon steel that has been treated to darken the metal all the way through. The treatment also makes the steel slightly more rust resistant.
These pans are usually very heavy gauge, high quality, professional goods, although they aren't particularly expensive. There is no coating to wear off since the steel itself has been darkened. These "blued" steel pans will rust if you let them sit around wet. They aren't to be confused with tin-coated steel, which is very shiny but darkens gradually with use. Tin-coated steel never gets as dark as "black" steel, however.
Gauge or thickness has a lot to do with how the pan bakes, whether it's dark steel or a light, shiny material. Heavier gauge is always better because it conducts heat in such a way that the batter or dough has a chance to bake on the inside before the outside burns. Since the blued steel pans on the market are invariably heavy gauge, they'll perform better than lighter gauge, coated pans, but it won't necessarily be because of the coating.
Dark steel -- either coated or treated -- does bake differently from its shiny relatives, but not in the way most people think. The one thing dark steel always does is produce a heavier or crisper outside surface than shiny pans.
This doesn't necessarily mean that it always cuts total cooking time, however. I've found that total cooking time, especially on thick breads and loaf-type cakes, will be about the same in a black steel pan as in a shiny one. In fact it's easy to be fooled by the quick crust formation into thinking your treasure is baked before it truly is.
And for most things the crust will be thicker whether you cut oven temperature as manufacturers usually recommend, or reduce baking time. This happens because the dark surface absorbs heat faster than a lighter, shinier one. The rest of the batter or dough cooks by conduction.
But you don't want a crisp or heavy crust on everything you bake.
Dark steel is terrific for pizza because it gets so hot so fast that it can outsmart the soggiest topping. Especially if you make a fairly thin-crusted pizza, coat the pan with olive oil and bake it at the bottom of a very hot oven, you'll have a crisp pizza crust that will approximate the professional variety.
On the other hand, you don't want your tender genoises or fluffy American-style cakes to have a crust. So dark steel doesn't make a lot of sense for conventional, round cake pans.
But a slightly heavy crust can be a nice thing on some heavier-battered cakes such as pound cake or fruit cake. In fruit cakes especially, a more substantial crust can help the cake to hold together under its weight of fruits and nuts.
Breads can be puzzling, and a lot depends on your preferences. Sometimes the crust is all, as in french bread. You can't beat the professional-quality, blued steel french bread pans for producing a substantial crust on long, baguette-type loaves. For lighter, American-style breads, however, you probably don't want a heavy crust. And heavier, whole-grain type breads usually produce a substantial crust no matter what kind of pan they're baked in. Dark steel will enhance this propensity, if that's what you like.
Tarts and pies can also confuse. But think of it this way: if you're baking something that threatens to produce one of those monstrous, pasty white crusts, use black steel. For quiches, for custardy pies, for gooey tarts with filling and crust that are baked at the same time, black steel will help send heat to the bottom of the pan, letting the crust bake and brown instead of giving in mushily to the filling.
For pie crusts baked "blind," however, you have to be careful. A very tender, rich pie dough with lots of butter, sugar and possibly egg yolks, may burn up when baked by itself in a dark pan. Such crusts are fragile in any case, and tend to become more so when baked in dark steel.
Lots of people swear by dark steel cookie sheets, but if you like your cookies on the gooey and soft side, find yourself a nice old-fashioned shiny sheet. Dark steel makes it hard to catch the cookies at that perfect stage when they're just barely done but not yet hardened to the ways of the world.
So you have to pick your spots when you're looking at new baking pans. The answer isn't invariably "yes" when the question is "should I buy dark steel?"