2. Pour the pure milk into a big container, add the white sugar, and heat it to 70℃ with low heat.

3. If it is made in the laboratory, it needs to be homogenized with a high-pressure homogenizer and repeated for three times. If it is homemade, this step can be omitted.

4. After homogenization, heat it to 90℃ with low fire and keep it for 10 minute for pasteurization. Self-made can be directly heated to 90℃ for pasteurization.

5. After sterilization, cool the milk (it can be cooled in water). When the temperature drops below 40℃, add pie yogurt into the milk and stir well.

6. Put the evenly stirred mixed solution into a constant temperature incubator, ferment at 40~45℃ for 6~8 hours, and then put it in the refrigerator for cold storage.