Production line introduction:After the raw milk is pretreated and cooled to the inoculation temperature, the starter is continuously pumped into the fermentation tank. After the tank is full, start stirring for a few minutes to ensure that the starter is evenly dispersed. The fermentor is insulated to maintain a constant temperature throughout the incubation period. In order to check the acidity development in the tank, a pH meter can be installed on the tank. The culture time of stirred yoghurt was 2.5-3hr, 42-43 ºC, and the ordinary starter was used (inoculation amount was 2.5-3%). In order to obtain the best product, when the pH value reaches the ideal value, the bacterial fermentation must be stopped, and the temperature of the product should be cooled from 42-43 ºC to 15-22 ºC within 30 minutes. At the same time, in order to ensure the ideal viscosity of the finished product, the mechanical treatment of the clot must be gentle. Cooling is carried out in the plate heat exchanger with special plates, which can ensure that the product is not subject to strong mechanical disturbance. After cooling to 15-22 ºC, the yogurt is ready for packaging. Fruits and spices can be added during the transportation of yoghurt from buffer tank to packaging machine. This is through a variable speed metering pump to continuously beat these ingredients into the yogurt, after mixing device. The design of the mixing device is static and hygienic, and ensures that the fruit and yogurt are thoroughly mixed. The fruit metering pump and the yoghurt feeding pump operate synchronously.