Ingredients:

  • 2 cups (475ml) heavy cream, pasteurized but NOT ultra-pasteurized (double cream in the UK)
  • 2 tablespoons (30ml) buttermilk, plain yogurt, sour cream, or even lemon juice (for acidity to encourage thickening)

Instructions:

  1. In a clean glass jar or container, gently whisk together the heavy cream and buttermilk (or yogurt/sour cream/lemon juice) until just combined.
  2. For faster results, warm the mixture slightly. If you have a yogurt maker, this is ideal. Otherwise, warm a large bowl and sit the glass jar with the creme and culture mixture into it.
  3. Cover loosely (or with a lid not fully tightened) and leave at room temperature (ideally between 65-75°F/18-24°C) for 24-48 hours. The warmer the room, the faster it will thicken. Check it after 24 hours; you're looking for a noticeable thickening.
  4. Once thickened to your liking, tighten the lid and refrigerate for at least 6 hours (or preferably overnight). This will further thicken the crème fraîche and halt the fermentation process.
  5. Enjoy! Use within 1-2 weeks, kept refrigerated.