Curing and Ripening Cheese
Many Cheeses are like wine, in that their finished character is determined not only by the original ingredients, but by the maturation process. The aging process whereby cheese is converted from a bland, tough, rubbery, fresh curd into a unique cheese with its own mature flavor, aroma, and texture is called, often interchangeably, curing or ripening. Depending on the variety, cheeses are subjected to different temperatures (36o to 75oF/2o to 24oC) and humidities (higher for mold-ripened cheeses such as Roquefort and blue). Certain cheeses are treated in such a way as to develop a rind, which is simply the dried surface of the cheese. Ripening times range from four weeks to two years or longer. Cheese becomes stronger in flavor as it ripens; these changes may be observed, for example, in the way cheddar cheese is labeled as mild, medium, or sharp.
Cheese flavor developed during curing and ripening originates from a combination of over 300 different volatile and nonvolatile compound. It is believed that some of these compounds originate from the milk, the activity of milk enzymes, and the starter bacteria. The skillful adjustment of curing techniques, along with the maintenance of the proper environment of temperature and humidity, creates the desired flavors, textures, and aromas of the multitude of cheeses available in our markets. During ripening, a number of elements may be manipulated to affect the final product. Added salt will draw out some of the remaining whey and inhibit bacterial growth, thereby slowing down the ripening process. Bacteria and molds contribute to the development of flavors, aromas, and texture. The mold Penicillium roqueforti added to homogenized while milk converts free fatty acids to smaller compounds, which impart the characteristic tangy flavor to blue cheese. The holes (eyes) in Swiss cheese are produced by gas-forming microorganisms that are active during the early part of ripening when the curd is pliable. Other processes that influence flavor during ripening include the hydrolysis of proteins to peptides (smaller protein molecules) and amino acids, the conversion of lactose to lactic acid, and the breakdown of fatty acids into shorter, volatile fatty acids.
Cheeses may exhibit different textures due to processing techniques during production, two of which are inoculation and kneading. The blue-veined cheese have been inoculated with mold spores, whose growth within the cheese creates the blue veins. Mozzarella and provolone are ropy in texture due to kneading, which is the pulling and stretching of the curd after it has been knitted.
