Crème Fraîche is sour cream's affable French cousin, smooth and creamy but with a bit less tanginess. Crème Fraîche is a type of thick cream made from heavy cream with the addition of buttermilk, sour cream, or yogurt. It contains anywhere from 10 to 45 percent butterfat that is reinoculated with naturally occurring ferments and lactic acid after pasteurization. This process initiates a “natural” fermentation. Crème fraîche has been described as having a tart but slightly nutty flavor.