Go to the supermarket and buy a small box of plain yogurt

Go home and find out the electric blanket used in the winter, plug in the middle gear

Use 2-3 bags of 250ml of fresh milk and that small box of yogurt mix, the best practical containers with lids, cover and seal the electric blanket on the heat, 8-10 hours after the opening of the success

Sour Milk The main points of the production: constant temperature, sealed fermentation