Emulsifying hard cheese and pasta water into a perfectly smooth sauce is basically a graduate-level course in Pasta Thermodynamics. The pan must be hot enough to melt the cheese evenly, but not so hot that it seizes—or, in the case of pasta carbonara, you wind up with a big bowl of scrambled eggs.
Carbonara recipes usually side-step the egg problem by having you toss the ingredients together in a large bowl, relying on the heat from just-cooked pasta and its water to thicken the sauce. This has never once worked for me, even when I get my trusty stick blender involved. Carbonara sauce isn’t just cheese and pasta water—it’s more like a custard. And why on earth would you try to cook custard with residual heat when double boilers exist? You’ve already got a pot of water going for the pasta; stick a bowl on top and you’ve got the perfect double boiler setup for silky-smooth carbonara. Here’s how to do it.
(A quick note: Make sure you find the right combination of pasta pot and heatproof mixing bowl before you start boiling water. The bowl needs to sit snugly on top of the pot without touching the water; if your usual pasta pot is a little too wide to accommodate a mixing bowl, use a large saucepan instead.)
Always start with the bacon (or guanciale if you’re lucky enough to have some), which needs at least 10 minutes to properly render over medium-low heat. While that’s happening, put a pot of salted water on to boil and whisk the sauce ingredients together in a wide, heatproof mixing bowl. For about 225 grams of dried rigatoni, I used 120 grams of bacon, one whole egg, 3 egg yolks, 1 1/2 cups of grated Parmesan and a heaping tablespoon of cracked black pepper.
When the pork is crisped up and ready to go, drop the pasta into the boiling water. About two minutes before it’s cooked to your liking, set the mixing bowl right on top of the pot and whisk the contents aggressively for 30 seconds to a minute, until the cheese melts and the yolks start to thicken.
Drain the pasta—reserving a little bit of water, of course—dump it into the bowl, and toss away. Add some cooking water and a few spoonfuls of pork drippings until the texture is just right, fold in the crispy pork bits and go to town.
To be perfectly honest, until now, I had never been all that excited about homemade carbonara. My most recent effort—a B*n App*t*t recipe—left the rigatoni swimming in a puddle of undercooked egg yolks, which I was not into. But double boiler carbonara fucks. The sauce is ridiculously silky, and since you need so little pasta water, it’s also richer and cheesier than any other version I’ve had. It is, in a word, perfect—and making it couldn’t be easier.