Is cheese making a precipitation reaction?
Yes, it is! According to “Food: The Chemistry of its Components” by Tom P. Coultrate, Ph.D., RSC (link below), “the fundamental process involved in cheese making is the precipitation of casein to form a curd”. Precipitation in soft cheese is normally induced by lowering the pH of the milk. In hard cheese, rennet is also added to speed up the precipitation and to form the curd.