This was my first time baking with crème fraîche (pronounced krem-fresh)! It was insanely simple to make, and I was amazed by how much the flavor changed over time. I added it as an ingredient to make chocolate ganache and it turned out perfectly delicious.
To make crème fraîche, place 1 cup of heavy whipping cream in a medium saucepan. Warm the cream over low heat until it reaches 105 degrees F. Remove the saucepan from the heat and stir in 1 tablespoon of buttermilk. Transfer the mixture to a small bowl and cover with plastic wrap. Let the bowl stand in a warm place until it is thickened, between 24 and 36 hours.
Stir every few hours. The cream will be ready when it has a nutty taste. I thought it tasted like nutty sour cream. Chill the crème fraîche in the refrigerator for a minimum of 2 hours before using and a maximum of 10 days.