Creme fraiche, that frou-frou French ingredient that I love on berries and stone fruits, stirred into soups and pasta sauces, and dolloped onto rich chocolate cakes, is so insanely easy to make that I absolutely cannot understand why people buy it. Tangy, smooth, and complex, it has a higher butterfat content than sour cream, making it decadently creamy. I have no earthly clue why people pay upwards of $6.99 for a 6 oz. tub of this when it is so easily made at home for a fraction of that cost. If you’ve ever had cream and buttermilk leftover from baking and don’t know what to do with it, here is your answer.
All you have to do is add 1-2 tablespoons of cultured buttermilk to every cup of cream and let it sit, uncovered, at room temperature for 12-24 hours until thickened to your liking*. Yes, this is ok to do- the good bacteria in the buttermilk/cream mixture keeps the dairy from spoiling, and they need to breathe a bit in order to thicken the cream. Generally, the only way you’ll get sick from this is if one of the ingredients is already spoiled. You’ll want to use good cream and good buttermilk – go for organic if you can, and definitely no ultra pasteurized stuff- and the longer you let it sit out, the thicker and tangier it will be. Mine usually looks like it’s doing nothing until between 12 and 18 hours, then it’s suddenly thick. Give yours a stir every now and again to check on it, and once it’s thickened to your liking, cover it and store in the refrigerator for up to a couple of weeks.
*Creme fraiche is generally a bit looser than sour cream, but with refrigeration, it can thicken up to the same consistency as sour cream if you let it culture at room temperature long enough.