As the old saying goes “age doesn’t matter, unless you’re a cheese.” In fact, ageing, sometimes called ripening, is the most important stage of cheese production. By allowing cheeses to rest in carefully controlled conditions, they develop the appearance, texture, flavour and aroma qualities that make them unique. During ageing, the bloom blossoms on Camembert, the holes burst into Swiss, and the veins shoot through Gorgonzola.
As a cheese ages, microbes and enzymes develop inside, breaking down proteins and milk fat into a complex mix of amino acids, amines and fatty acids. Ultimately, these actions transform the texture of the cheese and intensify its flavour.
To develop their unique attributes, most cheeses require ageing periods of two weeks to two or more years. In general, the longer a cheese is aged, the more firm, sharp and distinctive it becomes. A Stravecchio Parmigiano Reggiano, for example, is aged 24 to 36 months, giving it a very complex nutty-fruity taste and a hard, gritty texture. The mildest cheeses, like ricotta, cream and cottage, are consumed fresh and not ripened at all.
During ageing, cheeses are stored in cellar or cave environments that are closely monitored for temperature and humidity. These factors vary depending on the type of cheese being made. For firm cheeses, high temperatures are typically used to expel excess moisture. When it comes to soft cheeses, cooler temperatures are used. Since they have higher moisture levels and are more hospitable to bacteria, they must be matured more slowly to avoid the risk of over-ripening.
In general, ageing usually takes place in environments with temperatures ranging from 10º to 15º C. Conditions of high moisture are the norm, with typical humidity levels extending from at least 80% all the way up to the high nineties.
It’s also interesting to note that some cheeses, particularly fine artisan and famous regional varieties, are tended to by affineurs. These “master agers” have their own cheese ripening recipes and secrets that vary even among the same varieties. Other cheeses are aged according to very strict PDO (Protected Designation of Origin) laws. The famous French Roquefort, for example, may only be aged inside the limestone caves of Mount Combalou. The unique environment inside these caves is responsible for Roquefort’s distinctive tangy flavour.
There are numerous types of ripening techniques used to produce the great many cheeses we enjoy. The two principle methods are called interior ripening and surface ripening.
For interior ripened cheeses, ripening begins from the inside of the cheese mass and moves outward. Once properly aged, these cheeses are hermetically sealed or coated with wax to prevent further oxygen action on the surface. Examples of interior-ripened cheeses include Swiss and Cheddar.
Interior-ripened blue cheeses, like Stilton, Roquefort and Gorgonzola, have additional bacteria and moulds introduced to them during the ageing period. Sometimes the microbes are already present in the air and simply allowed to grow on the ripening cheese, and other times Penicillium moulds (roqueforti, glaucum) are injected into the curd. These moulds then grow in small fissures in the cheese, creating the characteristic blue-green veins, sharp flavour and creamy-crumbly texture.
With surface-ripened cheeses, ripening begins on the outside and eventually progresses inward. Microorganisms are rubbed onto the outer surface of the cheese to encourage the growth of a skin or rind. Examples of surface-ripened cheeses include bloomy-rinded varieties like Brie and Camembert, as well as washed-rind varieties like Munster, Morbier and Chimay, which are periodically washed in saltwater brine while ageing. The brine, sometimes seasoned with spices or wine, carries flavours into the cheese and also nurtures bacterial growth. In the case of Limburger, the growth of Brevibacterium linens imparts a very pronounced odour and flavour.
So as you can see (or smell), when it comes to cheese, age does matter.