Production of hard cheeses
The basic principles involved in cheese manufacture have remained the same for over 1000 years.
The milk is firstly heat treated to kill off any harmful bacteria that may be present. Starter cultures of special bacteria are then added to the milk and their growth “ripens” the milk and helps to develop the desired flavours and aromas.
Rennet is then added to the milk which helps it to coagulate and turn into curds and whey. Rennet was traditionally extracted from calves stomachs, but is now artificially produced from vegetarian sources.
The curds and whey are then heated to a high temperature and salt is added to produce the correct texture and flavour.
The cheese is then pressed to force out the whey, and to give it its final shape. The cheese is then left to mature and the longer the cheese is left in storage the more mature the flavour becomes.
Production of soft cheese
Soft cheeses fall into two categories: ripened e.g. brie and fresh (unripened) e.g. cottage cheese.
Soft cheeses are made from heat treated milk which is fermented by the use of specific bacteria.
Artificial rennet is sometimes used to produce a firmer texture.
Fresh cheeses are ready for use as soon as the manufacturing process is complete but ripened cheeses are allowed to mature in temperature and humidity controlled rooms for up to one month.
Nutritional value
Cheese is a concentrated source of many of the nutrients in milk. During the usual cheese making process, the water insoluble components of milk e.g. the milk protein - casein and fat, remain in the curd and the water soluble constituents e.g. carbohydrates, salts, and proteins smaller than casein, remain in the whey.
The amount of various nutrients retained in the curd and whey depends on the type of cheese manufactured, the type of milk used and the manner of coagulation.
The enzymes and bacteria involved in ripening of each specific kind of cheese may also alter the nutrient content of the end product.
