What key attribute differentiates aged cheese from fresh cheese?

Aged cheese is distinctly characterized by its maturation process. The aging period allows the cheese to develop more complex and stronger flavors due to the breakdown of proteins and fats within the cheese, a result of the activities of bacteria and enzymes during aging. This transformation leads to a richer taste profile and often a firmer texture compared to fresh cheese, which is typically soft, mild, and has a higher moisture content since it is consumed shortly after production.

The other options do not universally apply to all aged cheeses: not all aged cheeses have higher fat content, as fat content can vary significantly regardless of aging; aged cheese can be made from various types of milk, including cow, goat, and sheep; and not all aged cheeses are blue; in fact, many aged cheeses are not blue at all and can come in a variety of colors and styles. Thus, maturity and the flavor development it entails is the central differentiating factor of aged cheese.