Whether it is homemade yogurt or using a commercial yogurt fermentation machine to make yogurt, the fermentation process is crucial. If you do not control the relevant fermentation factors, you may not be able to make delicious yogurt. Normally, the temperature of the yoghurt fermentation environment is controlled between 38-45 ° C, and the fermentation time takes about 8-12 hours to complete the fermentation.
What are the factors that failed the fermentation of yogurt?
1.Yogurt fermentation container and temperature
When the overall temperature of yogurt fermentation is higher than 47 ° C, yogurt fermentation often fails. This is because the fermenting bacteria cannot tolerate high temperatures. When the growth environment temperature exceeds 50 ° C for a long time, it will cause inactivation.
Solution: Reduce the fermentation environment temperature of yogurt, control it between 35-45 ℃, add a bag of fermentation bacteria again, and continue fermentation
2. Yogurt fermentation temperature is low, fermentation time is not enough
Fermentation bacteria can ferment yogurt in the range of 28-46 ℃. But the fermentation time will be very different, for example, at 28 ℃, it takes more than 24 hours to ferment successfully; under about 45 ℃, it only takes about 8 hours to ferment successfully. If the fermentation temperature is low and the fermentation time is short, it will cause the fermentation of yogurt to fail.
Solution: 1. Continue the fermentation, if there is a weak sour taste, then continue to ferment for 2-4 hours; 2. Increase the temperature of the fermentation environment to minimize the fermentation time.
3. Yogurt has a lot of porosity, or has a noticeably bitter taste
This situation is generally caused by the contamination of yogurt with bacteria. The yogurt just made has a lot of pores inside, and there is a lot of whey. This situation can be determined to be caused by gas-producing yeast contamination. The state of the yogurt just made is no problem, but it has a bitter taste, which can basically be determined to be caused by the growth of psychrotrophic bacteria.
Solution: Milk products in this state are not recommended for consumption and should be discarded directly;
Producers can change milk, and the yoghurt fermentation machine must be strictly sterilized to re-make yogurt.
4. Yogurt has obvious graininess and poor taste
Yogurt made by the yogurt fermentation machine has a poor taste and is accompanied by a grainy feeling. It is generally caused by two reasons: 1. Insufficient mixing of milk and strains, which leads to the fermentation of strains, forming a grainy feeling; 2. The milk used for making yogurt is not pure milk and contains additional ingredients, such as high calcium milk.
Solution: 1. Stir until the fungus powder is added to the milk to completely dissolve, it is recommended to stir for more than 2 minutes; 2. Do not use dairy products containing additional ingredients to make yogurt, such as high calcium milk, breakfast milk, etc., but use pure milk.