Homemade crème fraîche is so easy that anyone can make it. Simply add a bit of cultured buttermilk to fresh cream and let it sit out at room temperature until the cream thickens from the lactic acid in the buttermilk. That’s it. The result: thick and delicious crème fraîche that is better (and far less expensive) than anything you can buy in your fancy gourmet market. Note: I like my crème fraîche best when made with cream that is not ultra-pasturized, but it can be challenging to find. If possible, buy cream from a local dairy that does not ultra-pasturize its products. If you do use ultra-pasturized cream, don’t worry. It will still be irresistable.