When the mixed starter of Lactobacillus bulgaricus and Streptococcus thermophilus is used, the temperature is kept between 465438 0℃ and 42℃, and the culture time is 2.5 ~ 4 hours, and the fermentation is terminated when it reaches the solidified state. Fermented and solidified yogurt needs to be moved to the freezing room at 0℃ to 4℃ immediately. Under such temperature conditions, the propagation speed of fungi can be inhibited.
Extended data:
The basic principle of homemade yogurt is to inoculate lactic acid bacteria into milk and let it reproduce at a suitable temperature (usually 40-42 degrees Celsius). Because of lactic acid, the acidity of milk fermentation broth gradually decreases. When the pH value reaches about 4.6, casein in milk will slowly precipitate and form delicate jelly.
Although other miscellaneous bacteria also exist in milk, compared with lactic acid bacteria, the number is too small to become a climate. Antibacterial substances such as lactic acid produced by lactic acid bacteria also make miscellaneous bacteria feel uncomfortable and unable to multiply in large quantities. This ensures the safety of yogurt.
People's Daily Online-Although yogurt is good, we should be wary of 8 problems in homemade yogurt.