What are used to produce yogurt?

* Milk: Yogurt is made from milk, which is a liquid produced by female mammals to feed their young. The most common type of milk used to make yogurt is cow's milk, but other types of milk, such as sheep's milk, goat's milk, or buffalo milk, can also be used.

* Yogurt culture: Yogurt culture is a live bacteria culture that is added to milk to convert it into yogurt. The most common type of yogurt culture is Lactobacillus bulgaricus and Streptococcus thermophilus, but other types of bacteria, such as Lactobacillus acidophilus, Bifidobacterium, or Lactobacillus casei, can also be used.

* Heat: Heat is used to kill harmful bacteria in milk and to create a favorable environment for the growth of the yogurt culture. The milk is heated to a specific temperature, usually between 180°F and 200°F, and held at that temperature for a period of time.

* Cooling: After the milk has been heated, it is cooled to a temperature between 110°F and 115°F. This temperature is ideal for the growth of the yogurt culture.

* Incubation: The milk is then incubated for a period of time, usually between 4 and 12 hours, depending on the desired thickness and tartness of the yogurt. During incubation, the yogurt culture will grow and convert the milk into yogurt.

* Refrigeration: Once the yogurt has been incubated, it is refrigerated to stop the growth of bacteria. Yogurt can be stored in the refrigerator for up to 2 weeks.