L. Gasseri DAIRY instructions

Dairy Instructions

Makes: 1 quart of cultured dairy
Time: 10 minutes preps, 36 hours culturing (1 day and 12 hours)

Timing is important. L. Gasseri takes 36 hours to ferment. It's best to start early in the morning or later in the evening. Otherwise, if you start in the afternoon, for example, fermentation will finish 36 hours later, in the middle of the night.)

You’ll need:

  • An appliance that can maintain a constant temperature of 100F for 36 hours, and which can ideally hold at least one 1-quart jar. Best two options are a sous-vide device or a yogurt maker with an adjustable temperature setting. (Other options that might work are: Instant Pot / slow cooker / brewing or kombucha warmer/heater - if these can be set to 100F for 36 hours and hold at least one 1-quart jar).
  • A glass jar that can hold at least 1 quart of liquid. Make sure that your utensils (jar, spoons, etc) are very clean.
  • A loosely fitting lid (or possibly a plastic wrap), to cover your jar.
  • 1 sachet of L. Gasseri Superfood Starter.
  • 2 tablespoons of a prebiotic fiber (such as Prebio Plus).
  • Dairy
    • For the 1st batch we recommend:
      • 1 quart ultra-pasteurized half and half, or
      • 1 quart ultra-pasteurized whole milk or 2%, or
      • 1 quart combination of the two
      • Can’t find ultra-pasteurized? Heat the dairy to 195F/90C for 10 minutes, then let it cool to 100F before starting the recipe. Most organic dairy is ultra-pasteurized. Use dairy without additives. Goat milk will yield a thin result. 
    • For the 2nd batch and onwards:
      • 1 quart of any ultra-pasteurized dairy mentioned above, or
      • 1 quart pasteurized half and half/whole/2%/combination of these


  1. In a glass jar, mix 2 tablespoons of prebiotic fiber (such as Prebio Plus) with the contents of 1 sachet of L. Gasseri Superfood Starter.
  2. Add approximately 1.5 cups of dairy (cold, or up to 100F). Whisk well to avoid clumping and for even distribution. Do not blend. 
  3. Stir in the remainder of the dairy, leaving some headspace. Mix/whisk well for even distribution. Do not blend.
  4. Cover lightly with a loosely fitting lid or a plastic wrap. (If using small individual jars, pour the mixture evenly into the jars, leaving some headspace, and loosely cover each jar with its own lid).
  5. Ferment at 100F for 36 hours, away from the airflow of air vents/heaters/air conditioning, etc., and away from other ferments. Do not stir while fermenting. Do not open the jar(s) while fermenting.
  6. After 36 hours, remove from appliance, let cool, then secure lid(s) and put in the fridge. Will keep in the fridge for up to 4 weeks. 
  • Reculture: To make a new batch, repeat these instructions but use 2 tablespoons of your previous batch of cultured dairy as your starter. (And don't forget the prebiotic fiber!) If the previous batch separated, use 1 tablespoon of the curds and 1 tablespoon of the whey (or 2 tablespoons of whey if the curd is too firm) as your starter.
  • Important tips: Don’t heat the end-product or stir it into a hot dish. If blending is needed, keep it to a minimum and at a low speed. L. Gasseri are living bacteria, and are sensitive to heat and to intense agitation.

Note: Store the starter culture in the refrigerator or freezer until you're ready to use it.

L. Gasseri

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