This post originally appeared in an edition of What’s the Difference?, a weekly newsletter for the curious and confused by New York City writer Brette Warshaw. Eater will be publishing all editions that parse food-related differences, though those hardly scratch the surface of the world’s (and the newsletter’s) curiosities: Sign up to get What’s the Difference? in your inbox or catch up on the full archive.
What’s the difference between...
Sour Cream and Creme Fraiche?
Sour cream, which has a fat content of around 20 percent, is made by mixing cream with a lactic acid culture; the bacteria thickens and sours it. It may also contain stabilizers, like gelatin or rennin, which aid in the thickening. Sour cream is less expensive than creme fraiche, and since it contains less fat and more protein, it will curdle if you simmer or boil it — so it’s best to use cold or room temperature, or to stir into a hot dish once it’s off the heat.
Creme fraiche — clocking in at 30 percent fat — is traditionally made with just unpasteurized cream, which naturally contains the bacteria needed to thicken it. However, in the United States, our cream must be pasteurized — so creme fraiche is made by mixing cream with fermenting agents that contain the necessary bacteria. You can actually make your own creme fraiche at home: mix together heavy cream and buttermilk, and let it hang out at room temperature until it reaches its desired thickness (around 8 to 24 hours). As it sits, the bacteria in the milk converts the sugars (lactose) into lactic acid, which lowers the pH of the mixture and prevents the formation of any unwelcome microbes.
Creme fraiche is thicker, richer (see: fat content), and less tangy than sour cream, and since it won’t curdle if you boil it, it’s great to use in soups and sauces. Or just spoon it into your mouth, unadorned.