How to make kærnemælk (buttermilk) at home

What is kærnemælk?

Kærnemælk (Danish), karnemelk (Dutch) and kjernemelk (Norwegian) all mean buttermilk. Traditional buttermilk was the liquid left after churning butter. Modern buttermilk is usually cultured: pasteurized milk is fermented with lactic acid bacteria, much as yogurt is, which thickens it and gives it a tangy taste.

How do you make buttermilk at home quickly?

1. Pour 1 tablespoon of lemon juice or white vinegar into a measuring cup.
2. Add milk up to the 1 cup line and stir.
3. Let it stand 5 to 10 minutes at room temperature until it curdles slightly.

Whole or 2 percent milk works best. This acidified milk is a substitute for baking (pancakes, biscuits, cakes), not a true cultured buttermilk. It tastes sharper and thinner.

How do you make cultured kærnemælk at home?

Stir a small amount of store-bought buttermilk that lists live active cultures into pasteurized milk (follow the starter instructions for the ratio), cover loosely and leave at room temperature until it thickens, which commonly takes about 12 to 24 hours (longer in a cool kitchen). Chill it, and keep a little as a starter for the next batch. A powdered mesophilic buttermilk starter also works. Use fresh, non-ultrapasteurized milk, and throw it away if it has mold, a strong off smell or is pink or slimy. Do not use yogurt culture; it needs different temperatures.

Can you make buttermilk without milk or acid?

Thinning plain yogurt with a little milk or water to a pourable consistency works as a baking substitute. Some bakers use cream of tartar; results vary. Plant milks can be soured with the same 1 tablespoon of acid per cup.

How is Dutch karnemelk or Danish kærnemælk used?

As a drink on its own, in pancakes, waffles and cakes, and in cold dressings.

How long does homemade buttermilk keep?

Refrigerate it in a clean, covered jar. There is no official figure; use homemade cultured buttermilk within a few days, and the acidified type should be used the same day or within a day or two. Smell it first and discard anything that looks or smells wrong.