How to Make Crème Fraîche (in One Easy Step!)

"For those of you who pay attention, yes, we did talk about this back in August. I just feel like minds weren't sufficiently blown that time around. Certainly, mine wasn't, so I thought I'd share my feelings on the matter. Me: "I'm going to need crème fraîche for the dinner I'm cooking tomorrow. But dangit if my local supermarket only carries heavy cream and buttermilk!" Buddy: "You know you can just mix heavy cream and buttermilk, let it sit overnight, and you've got crème fraîche, right?" Me: "Auauhungh?" Mind = blown. OK, that conversation didn't really happen, but the first time I mixed buttermilk and heavy cream and let it sit overnight until it became thick and creamy, my mind was honestly more blown than it had been since finding out that Brad Pitt and Edward Norton share a body. And here I thought making ricotta was easy! I played around with the ratios of cream to buttermilk quite a bit and in the end found that it doesn't really matter all that much. Add more buttermilk and you'll need less time for it to thicken (but it'll be less creamy). Add more, and it takes longer, but tastes better. One tablespoon per cup (that's a 1:16 ratio) was about the perfect balance for me. It gets super rich and creamy at right about the 12-hour mark. You can also halt the process early by just refrigerating it to stop the bacterial action. This is useful if you want a thinner Mexican-style crema agria for drizzling over tacos or sopes. For those of you worried about cream spoiling at room temp, that's the idea: it's the good bacteria from the buttermilk multiplying in there that prevents the dangerous bacteria from taking over. And let the mind-blowing begin. Commence countdown...."