BASIC CHEESEMAKING

Cheese is made from milk; in the main it is made from cow's milk but there are many varieties made from sheep's milk and goat's milk. Cheese is also made from the milk of buffaloes (Mozzarella is one), reindeer, asses, camels and most domesticated herbivores (let it be added, however, that it is unlikely that your local cheese supplier is going to be pressing huge stocks of reindeer's, asses' or camel's milk cheese upon you).

The basic principle involved in making all natural cheese is to coagulate or curdle the milk so that it forms into curds (milky white lumps) and whey (a thin liquid). As anyone knows who has left milk unrefrigerated for a period, milk will curdle quite naturally. The milk sours and forms into an acid curd. This is the basis of nearly all cheesemaking (whey cheeses are the exception, being made from the whey of the milk rather than the curds). Today's methods help the curdling process by the addition of a starter (a bacterial culture which produces lactic acid) and rennet (a substance obtained from the stomach linings of young calves which contains a coagulating enzyme which speeds the separation of liquids and solids).

The least sophisticated cheeses are the fresh, unripened varieties typified by Cottage Cheese. These are made by warming the milk and letting it stand, treating it with a lactic starter to help the acid development and then cutting and draining the whey from the cheese. The cheese is then packed and marketed without further ripening. This is the simplest, most basic form of cheese.

Cheeses that undergo a ripening process (also known as a curing, maturing or ageing process) are all treated with rennet. Before the ripening process begins, they go through a sequence of operations which, while following the same general pattern, varies from cheese to cheese. Basically, this sequence is:

1. Milk is warmed
2. A starter culture and rennet are added
3. The milk coagulates into a single huge curd
4. The curd is stirred and cut to drain off whey
5. The curd is heated, sometimes pressed, to remove more whey
6. The curd is moulded and shaped into a cheese, salting taking place before or after this process
7. The cheese is matured under controlled conditions.

Variations on the cheesemaking process start with the milk. It may be taken from a morning or an evening milking, or from a combination of both. Before the milk is set a colouring agent may be added to it, the most widely used one being annatto, a vegetable dye taken from a South American plant. This produces an amber orange-yellow colour. The milk may be skimmed of its cream content or have cream added to it. The quality of the milk, its richness, its acid content, the degree to which it is heated, even the breed of cow that is used, the grass she feeds on, the soil and the climat - Qall these factors influence the final cheese.

So does the amount of rennet used, the way the cheese is pressed, the heating of the curds, the degree of salting, the number of times the cheese is turned from one side to another while it is maturing, how the cheese is brushed, scraped or washed and the ingredients used to treat the cheese (Appenzell is immersed for a period in a mixture of white wine and spices, Maroilles is bathed with beer, Feta matures in brine and so forth.)

During the ripening period, the two most important factors are the length of the maturing time (it can vary from two weeks to seven years) and the temperature at which the cheese is matured.

It is during this time that the microorganisms play their part. They may be present naturally in the milk or in the atmosphere of the curing room, or they can be artificially introduced.

Blue veined cheeses are inoculated with a Penicillium spore which creates their aroma, flavour and bluish or greenish veining. Such cheeses are internally moulded and ripen from the inside out. On the other hand, cheeses such as Camembert and Brie have their surfaces treated with a different type of Penicillium spore which creates a downy white mould (known as a bloomy or flowery rind): this makes them surface ripened cheeses.

Many surface ripened cheeses have their surfaces smeared with a bacterial broth. With others the bacteria is in the atmosphere of the curing chambers. These cheeses are called washed rind varieties as they must be washed regularly during their ripening period (longer than for Camembert or Brie) to prevent their interiors drying out. The washings also help promote an even bacterial growth across the surfaces of the cheeses. As this washing can be done with liquids as diverse as salt water and brandy, it also plays a part in the final flavour of the cheese.

The rinds of the cheeses are formed during the ripening process, many quite naturally. Some, as we have seen, artificially. Rinds may be brushed, washed, oiled, treated with a covering of paraffin wax or simply not touched at all. Traditional Cheddars are wrapped around with a cotton bandage. The rind's basic function is to protect the interior of the cheese and allow it to ripen harmoniously. Its presence thus affects the final flavour of the cheese. Salting plays an important role in rind formation. Heavily salted cheeses develop a thick, tough outer rind, typified by the Swiss range of cheeses. Cheddar, another natural rind cheese, is less salted than the Swiss varieties, and consequently has a much thinner rind.

Adapted from "The Cheese Book," by Richard Widcome. Chartwell Books (Seacaucus, NJ), 1978.