Ripening or aging . The cheese is allowed to ripen or age for various periods of time. During this time, bacteria continue to grow in the cheese and change its chemical composition. Bacteria use the curd as food and release waste products, resulting in flavor and texture changes in the cheese. The biochemical changes in ripening are regulated by the moisture content, salt concentration, and the species of microbes present.
Proteolysis is the most important event in ripening.
The type of bacteria active at this stage in the cheesemaking process and the length of time the cheese is aged determine the type and quality of cheese being made. Many different proteases can be used to coagulate milk. However, the best are those that cut kappa casein. Kappa casein is an important component in maintaining the micelle structure of milk. If the kappa casein is cut, the micelle structure is lost and milk coagulates.