Using a yogurt machine to make yogurt may not necessarily lead to success. The key depends on the method. Some people do it the right way and succeed the first time. If you try and fail many times, you need to find out why. So why does yogurt fail to ferment? What is the reason why the yogurt machine fails to make yogurt?

1. Inactivation of bacteria: If the fermentation of yogurt fails, the first thing to think about is the inactivation of bacteria, because the bacteria cannot play a role and the milk cannot be fermented. During the storage process, attention should be paid to the preservation of the bacteria, which must be at low temperature, preferably in a frozen environment.

2. Poor quality of milk source: Not all milk can be used to ferment yogurt. Some milk cannot meet the fermentation requirements. It is recommended to buy pure milk, preferably pasteurized milk, because pasteurized milk has been sterilized.

3. The temperature does not reach 40 degrees: the bacteria will only ferment under a certain environment. Usually, the fermentation temperature needs to be between 35-45 degrees and constant temperature. If the temperature fluctuates high and low or the temperature cannot be reached at all, fermentation will fail.

4. Insufficient fermentation time: Using bacteria as a starter, it takes 8-12 hours for milk to ferment into yogurt. Using yogurt as a starter will take 6-8 hours to complete fermentation.