- 1 cup heavy cream
- 1/3 cup buttermilk, sour cream, or Greek yogurt
- 1 teaspoon homemade vanilla extract (if using for a sweet purpose, otherwise leave it out)
- Put heavy cream and buttermilk/sour cream/yogurt (and vanilla, if using) in a jar or container with a tight lid. Cover securely and shake 15 seconds.
- Set aside at room temperature for several hours (ideally 12-24), shaking every once in a while until very thick. Cream will thicken faster if the room is warm.
- Stir well and refrigerate before serving. Store in refrigerator for up to 2 weeks.