Landlord, the finished yogurt contains beneficial live bacteria, so the nutritional price is high. Living bacteria will continue to grow and ferment at room temperature, and after a long period of division and production, they will enter a recession period, which will lead to the reduction of the nutritional price of yogurt. In order to keep the number of viable bacteria in yogurt, it must be frozen. But even if it is frozen, it is still not enough to ensure long-term activity. I don't believe that yogurt can be preserved for a long time without any preservatives and antibiotics. I only believe that the more antibiotics you add, the longer it will last. Now the dairy industry is constantly exposed, especially the yogurt industry. I only trust my own hands now. The pure milk I bought is made of mushroom powder and pure milk, which can be made into yogurt, proving that the quality of pure milk is no problem. It is suggested that the landlord use Bear's yogurt machine, Bifidobacterium nucleolus yogurt starter, Mengniu Yili's pure milk and DIY production. It's delicious, and the key is hygiene. Drink once every 2-3 days, and the activity content is relatively high.