Chef John's Crème Fraîche
Crème fraîche is so easy to make at home with just heavy cream and cultured buttermilk. Sure, it takes a couple of days to make, but the effort is minimal, and the payoff is marvelous! It has a higher fat content than sour cream which makes it less likely to curdle when you cook with it.
heavy cream
2
cups
cultured buttermilk
3
tablespoons
 Combine cream and buttermilk in a glass jar. Cover tightly with cheesecloth (or any breathable material) and let sit at room temperature (70 to 75 degrees F (21 to 24 degrees C)) until thickened, about 24 hours.
  Stir mixture, then screw on the lid. Refrigerate for 24 hours before using.
