This recipe makes thin crème fraîche. I made thick crème last month. Chef Thomas Keller adds thin crème fraîche to his omelets . I added it to omelets and a sauce. This is a great recipe. People can use a paper cone or plastic squeeze bottle to use the crème as a condiment.
The science behind cultured dary foods, including sour cream, is fairly straight-forward. Certain non-pathogenic (not disease-causing) bacteria like to feed on the lactose present in milk and cream. Those bacteria produce acid and that acid reduces the pH of the milk or cream. The reduced pH coagulates the protein, which partially solidifies the product. Acid without bacteria can be used to coagulate dairy proteins, as with one version of home-made ricotta cheese that calls for vinegar.
Bacteria make acids by eating lactose that are analogous to using lemon juice or vinegar to make ricotta or buttermilk. The acids cause curds to form which make cheese . The bacteria cause the cream to coagulate.
- Mix 2 cups buttermilk and 1 cup heavy cream. Put bowl over a pan of hot water and heat to 85°F.
- Pour warm mixture into a glass bowl; partially cover. Let stand at room temperature for 6-8 hours.
Here are the proportions:
- 1 cup cultured buttermilk : 1/2 cup heavy cream (not ultra-pasteurized)
I chose to wait 24 hours rather than heat the buttermilk and cream because I needed a small pan. A shallow volume of liquid appears heats instantaneously. There is a link to my recipe below. Waiting 24 hours works perfectly.
Bain-Marie (Metal Warmed Too Quickly, Glass Worked, No Bain-Marie Is My Choice, Wait 24 Hours)
There Are Some Curds When The Cream And Buttermilk Are Over-Heated
Waiting 24 Hours Eliminates The Bain-Marie
Download The Recipe:
1. Jeni Wright, Eric Treuille: Le Cordon Bleu Complete Cooking Techniques (New York: William Morrow And Company, Inc., 1996), 46.
2. Jacques Pépin: Jacques Pépin’s Complete Techniques (New York: Black Dog & Leventhal, 2001), 143.