CHEESE - MANUFACTURING PROCESS OF CHEESE
HISTORY
According to legend, cheese was first made accidentally by a traveling shepherd, who carried milk in a pouch made from the stomach of a sheep. The combination of heat of the sun with the enzyme rennin present in the lining of the stomach curdled/separated milk into curd (a soft was then drained to remove the excess liquid or whey mass or junket) and whey. Curds are coagulated proteins (casein) known as cheese. This soft mass containing protein and fat was then drained to remove the excess liquid or whey and dried in the sun to form a harder mass which could be eaten fresh or salted and stored for later use when the food supplies were less plentiful.
DEFINITION
Cheese may be defined as the fresh or matured product made by coagulating any or a combination of any of the following substances, namely milk, cream, skimmed milk, partly skimmed milk, concentrated milk, reconstituted dried milk and butter milk, and then partially draining the whey, resulting from any such coagulation.
Cheese Making is a very convenient method for converting a considerable part of the milk nutrients into a product that is less bulky, will keep well, is of a high nutritive value and is palatable and easily digestible.
There are over 400 varieties of cheese listed as being made in different parts of the world. They are made from a variety of different milks from animals like cow, sheep, goat. buffalo and others, by different methods of manufacture, are ripened for different periods of time in different conditions and are made in different sizes from a few ounces to the very large size of 70 lbs or more. They will also differ by colour, texture, hardness, odour and taste.
MANUFACTURING PROCESS OF CHEESE
Basically cheese is made by forming a curd by the action of the enzyme rennin, or acid, upon pasteurized milk. This curd is then ripened by enzymes produced by the addition of a culture of microorganisms. During ripening, the constituents of the curd are modified to produce characteristic flavors and textures.
Heating the milk
The temperature should not be less than 10°C and should not exceed 65°C. The optimum temperature is 37°C (At 10°C, the cheese will be soft, while at 65°C, the cheese will be hard).
Curd formation
This is brought about by the addition of rennet (rennin), curd or lactic acid producing bacteria (Suitable cultures of microorganisms may be added at this stage to bring about ripening or souring of the milk).
This mixture may be held at varying temperatures during what is known as "setting" period which is 20-26°C (70-80°F) for soft cheeses and 30-32°C (86-90°F) for hard cheeses.
The setting temperature, the quantity of rennet added and the amount of acid produced by the microorganisms largely govern the rate at which the curd and whey separate, and also affect the texture of the curd.
Cutting the curd
The curd is then cut remove moisture. Then the whey is separated - finer the curd is cut greater is the whey separation.
Cooking the curd
Coking the curd helps in the removal of whey. The curd begins to compact and become elastic, rather than crumbly. During heating, the lactic producing bacteria increase Higher the temperature, firmer the cheese becomes e.g. Cheddar becomes firm at a temperature of 38°C (100°F).
Separating the curd
All excess whey is finally removed from the curd.
Curd piling
The curd is cut into blocks and piled up. This allows the curd to form a solid mass and further development of the starter culture. The curd begins to develop characteristic properties of texture and flavour.
Milling and Salting
The now-dry curd is milled into small fragments and salt is added - either as fine salt or brine solution (Sometimes in aqueous solution which permits homogenous absorption). Salting influences many factors-flavour, moisture content and texture; also checks lactic acid formation by inhibiting acid producing organisms (also reducing risk of spoilage) and at the same time permits the development of specific ripening microorganisms.
Pressing the curd
Pressing the curd gives cheese its characteristic shape and texture. This cheese is called "Green cheese (Immature cheese)"
Maturing (Ripening)
In this stage, the green or immature cheese develops the characteristic texture and flavour of its variety. The green cheese is placed in well ventilated rooms on racks. The temperature is maintained at 13°C and at a humidity of 80-90%. Then the bacteria, moulds etc. are added to
bring about changes. The fresh cheese is covered with wax or other things to prevent the moisture loss.
Ripening is a change in the physical as well as chemical properties such as aroma, flavour, Texture, composition ete. which occur between the time of precipitation of the curd and the time when the cheese develops its characteristics. Ripening is the process that converts freshly made curds into distinctive, flavourful cheese. This ripening is brought about by certain bacteria or moulds that are introduced during manufacture. Much of a final cheese's final character is determined by the kind of ripening agent and the way it acts on the cheese.
Following changes take place during ripening.
1. Lactose is converted to lactic acid.
2. Proteins are broken down to simpler components-amino acids.
3. Fats are converted to fatty acids.
4. CO2 is formed that produces holes, as in Emmental cheese.
5. Development of aroma/flavour.
6. Change in colour.
7. Change in texture-hard to soft-due to the action of bacteria or moulds (Brick - Bacteria, Stilton and Roquefort-Mould etc.).
Comments