You deserve the real deal
I’m a huge fan of substitutions in the kitchen. A spoonful of mashed banana instead of an egg? Sure. White sugar and molasses instead of brown sugar? Bring it on. However, there’s one ingredient that proves tricky to sub perfectly: creme fraiche. To really get the right flavor, the perfect texture, the ideal—dare I say it—mouthfeel, you should DIY. The soured cream is produced by adding a starter culture to heavy cream, then leaving the mixture to thicken; if you’ve ever made your own yogurt, you’re familiar with this process. Unless you’re near a large, well-stocked grocery store, finding creme fraiche in the US can sometimes prove tricky. While you could satisfy a need for the tangy cream in a pinch with Greek yogurt or sour cream, neither is going to coat your tongue with the same creamy, French-y richness as creme fraiche.
You may not be able to find creme fraiche at the store, but I bet you can find cultured buttermilk and heavy cream. Got them? Good, because they’re all you need for DIY creme fraiche. Well, those ingredients and several hours to spare.
Pour 3 cups heavy whipping cream and 3 tablespoons cultured buttermilk into a bowl and stir until just combined. Regular buttermilk should work in this recipe as well, but cultured buttermilk really is best, becauseunlike regular buttermilk, which is tangy with naturally occurring lactic acid, cultured buttermilk contains additional bacterial cultures, which will help the creme fraiche along. Transfer the mixture to a glass container and cover. Store the mixture at room temperature—your kitchen counter is a good place for this, as long as it’s not in direct sunlight—and let the mixture stand for 8 hours.
After 8 hours, take a peek under the lid. The creme fraiche should be much thicker than when you left it. If you’re happy with the consistency, transfer the container to the refrigerator. If you like your creme fraiche on the thicker side, recover the container and let the mixture sit out for longer, checking again after another 3 hours (8 hours total) or another 16 hours (24 hours total). Move the container to the fridge when you’re satisfied with the creme fraiche’s thickness, but don’t leave it out for more than 24 hours.
DIY creme fraiche will stay fresh in the fridge for 2 weeks.