How do you explain the long shelf life of dairy products?

The advantage of industrial production is the ability to keep products completely
clean. This is how dairy products are manufactured all over the world. The milk (and
other raw materials) are pasteurized (heated to a high temperature), which ensures
the product’s microbial cleanliness.

From the moment the product is pasteurized it is no longer exposed to the outside
air, which guarantees its absolute cleanliness when it is packaged. The product stays
this way until it is opened.