Swedish Filmjölk is made from a special culture that makes a unique drinkable yogurt. This traditional cultured dairy is similar to kefir in some ways, but it's smooth and pleasant.
Begin with a quart of milk. If you’re using raw milk, shake it to mix the cream back in (it naturally separates during the culturing process). Both pasteurized and raw milk work well for this recipe, though pasteurized milk ensures better control over the culture.
Mix about 1/4 to 1/2 cup of Filmjölk culture (or the same amount of already made Filmjölk) into the milk. Stir thoroughly to incorporate the culture. If using freeze-dried culture, simply add it directly to the milk.
Cover the milk and let it sit at room temperature for 1-2 days, ideally between 65-75°F. The length of time will depend on how thick you want your Filmjölk. After 1-2 days, it should have thickened and developed a tangy, slightly buttery flavor.
Once thickened to your liking, you can enjoy the Filmjölk immediately or store it in the refrigerator for up to two weeks.
Add flavorings such as crushed fruit, honey, or even maple syrup if desired. Filmjölk can also be eaten as a breakfast cereal with muesli or used in baking recipes that call for buttermilk, sour cream, or yogurt.