1) Wash coarse glass bottles or porcelain bottles (wide-mouthed bottles can't be used, because the bottle mouth is too big and easy to be polluted by miscellaneous bacteria), put milk on it, cover the bottle mouth with a clean double-layer plastic film, tie it with a string, and loosen it, because a lot will be produced in the bottle when heated.

If the steam is tied too tightly, the film will break and pollution will easily occur.

2) Put the glass bottle with milk into the pot and boil it for 30 minutes. Soak it in water without cover and then take it out.

It's so cold that the back of your hand is not hot.

3) 2% ~ 4% of fresh pure yogurt sold in the market, such as Jiabao brand pure yogurt and Qinnong brand pure yogurt. Join and buy

Immediately after yogurt, tie the plastic film tightly to ensure the oxygen-free environment in the bottle.

4) After room temperature (above 30℃ in summer) 10 hour, fresh milk solidifies like tofu and yogurt.

5) Put the yogurt bottle into the refrigerator and refrigerate it at 0 ~ 5℃ for 2 ~ 4 hours, then it can be eaten.

White sugar can be added during sterilization or when eating, depending on personal taste.

You can make a small bottle separately, and if the curd is good, you can keep it as a strain, but you can't use it many times because you can't guarantee aseptic operation at home.

The strain can be put in the refrigerator. For example, the film on the bottle mouth bulges, which produces gas, indicating that gas-producing bacteria have entered and can only be eaten.

Can no longer be preserved as a strain.