Oven – Have I over- or under-cleaned the cast iron dutch oven

With enameled cast-iron, I don't bother to heat the pot before adding the oil. For something that's open-pored, like plain cast-iron or carbon steel (like an old-school crepe pan), it's better to preheat the pan. I can't see any chemical advantage to preheating enameled, as it's inert and non-porous. Of course everything DOES need to be properly hot before you add the meat.

I can take or leave letting my roast get to room temp when doing a braise. It's going to be in the oven/pot long enough that it's going to be cooked to 200+ degrees all the way through no matter what. The only possible advantage of letting it warm up on the counter is that it will take marginally less time to cook. And by marginally, I mean you probably won't even notice, on the scale of pot roast cooking time. For a steak or a rib roast where you want the middle warm without the outside being totally dry and charred, room temp helps a lot.

The only real tip I can give on pot roast is to use the right cut of meat. You want something from the shoulder, which usually means chuck. It has an excellent mix of rich meaty flavor, collagen/connective tissue (which makes that gelatin thats critical to the silky mouthfeel of pot roast and BBQ), and fat. You can also use something from the leg (shank) or tail, which also have loads of connective tissue, but they're usually a little low on actual meat. If you get the right cut of meat and cook it low and long enough to get that collagen rendered, it's pretty hard to mess up the rest of it.

The biggest practical differences are going to be:

• Nothing sticks to a well-seasoned cast iron pan. Everything sticks to cast aluminum, even the brands that call themselves non-stick. (I know because I've tried a few of them.)

• While it's true the cast iron can crack, rust or chip if not properly cared for, aluminum is reactive and scratches easily, and even if you get one of the newer anodized ones, you lose the benefits of that as soon as the surface starts to chip and peel (which it will). Cast iron will last much longer when properly maintained; I've seen some that are decades old and heard about some that are more than a century old.

• Aluminum has better conductivity and will, in theory, provide more even heat than cast iron. However, every cast aluminum vessel I've ever used has had major problems with hot spots. Basically, both are poor choices in this respect, except in the oven, where hot spots are essentially a non-issue; if your oven is like mine and the element turns on and off to maintain temperature, you'll get much better results with a cast iron dutch oven because it will hold its temperature while the element is off.

• Cast iron also works great with induction cooktops, aluminum doesn't work at all. [Cast] Aluminum really works best on standard metal cooktop stoves, although it's okay for glass as well. I say okay because most glass cooktops tend to have elements that go on and off, so depending on your particular stove, this might lead to uneven heat when using any kind of aluminum.

• Cast iron is heat-resistant. You mention the melting point, but it's more complicated than that; make sure you check the specifications on whatever cast aluminum you're thinking of buying, because a lot of it isn't even oven-safe (and if it is, it's only safe up to 400° F or so). The term "dutch oven" can be quite a misnomer for those pieces as they can easily warp or crack at high temperatures. Spun aluminum is obviously much worse but cast aluminum is only marginally better.

• On the plus side, cast aluminum is obviously much lighter than cast iron and requires less care. Enameled cast iron is also easy to care for but is obviously much more expensive than both regular cast iron and cast aluminum.

In your case, it would seem that your two primary requirements (caramelizing sugar and roasting meat) are at odds with each other. For roasting, you want a very steady, even heat. For caramelizing sugar you need precise control, you need to be able to reduce the heat very quickly when you hit the melting point. Cast iron would be absolutely terrible for caramelization, but is a far better choice for roasting.

Personally, I use a regular (non-enameled) seasoned cast iron pot as a dutch oven and just use a small light stainless steel saucepan when I need to do something like caramelize sugar. I'd suggest you do the same, unless you're really low on space and genuinely need one piece of cookware to do it all.

Honestly, the only thing that cast aluminum really has going for it is its price. The ease of maintenance is overshadowed by the fact that the pieces don't tend to last that long, and everything else it's good at is handled equally well or better by stainless steel with an aluminum or copper core. The few pieces of aluminum (or cast aluminum) cookware I still own tend to sit at the bottom shelf at the very back and gather dust, but YMMV.