Kwark

Warm the milk to 80°C, then allow to stand for 30 minutes.

Cool to 20°C, then stir in 3 tablespoons of sour cream.

Leave at room temperature (20°C) until the next day.

Using a cloth, squeeze out the liquid — the more you squeeze, the drier it becomes. 1 litre yields roughly 1/10 to 1/5 of the original volume.