Cheese

Cheese

According to legend, cheese was first made accidentally by a travelling 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 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.

Classification of Cheeses

Cheese may be classified under one or a combination of the following:

1.      The Country of origin

It is helpful to be able to classify cheese in this way, so that cheeses from different countries may be featured on the menu or cheese board of a restaurant.

2.      The method of manufacture

This system of classification is based on how the cheese has been manufactured, which in-turn determines the type of cheese produced. This classification identifies six main groups of cheeses – hard, semi-hard, soft, surface mould, surface slime and blue-veined (i.e. internal mould and includes acid coagulated cheeses). The important features in the manufacture of cheeses are:

·        The type of milk being used.

·        Whether the milk is ripened or not.

·        Whether rennet is added or not.

·        Whether the curd is scalded (stirred) or not.

·        Whether the cheese is pressed or not.

3.      General aspects

The general appearance of a traditionally made cheese is important for the recognition of it. Cheese is recognized by:

·        Size: Traditionally, cheeses have always been made of the same size and shape; hence easily recognizable e.g. English Cheddar is usually made in the shape of a small drum being 13” high and 11” in diameter. The English Leicester is usually made in the shape of a wheel being 4” high and 18” in diameter.

·        Colour: The colour of the cheese–internally and externally–is another point of recognition e.g. the English Stilton has a wrinkled brown coat and a blue-veined creamy-white body. The Dutch Edam has a red wax coat and a rich straw coloured body.

·        Flavour: The flavour of the cheeses, when fully mature, is quite standardized, although only minor changes in the manufacture can affect the flavour considerably. The basic aspects of flavour such as cheese being mild, very rich, salty and tangy are usually quite evident to most people, but the description given by the cheese makers like “slightly nutty”, “mildly fruity” etc. needs experience to appreciate.

·        Texture: This is seen when examining the cut surface of a cheese and in greater detail, when cutting a portion of the cheese. Typical textures are hard, semi-hard, semi-hard with gas holes, rubbery, close, loose and crumbly, buttery and open.

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 flavours and textures.

1.      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).

2.      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.

3.      Cutting the curd

The curd is then cut to remove moisture. Then the whey is separated – finer the curd is cut, greater is the whey separation.

4.      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).

5.      Separating the curd

All excess whey is finally removed from the curd.

6.      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.

7.      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.

8.      Pressing the curd

Pressing the curd gives cheese its characteristic shape and texture. This cheese is called “Green cheese (Immature cheese)”.

9.      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 etc. 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. Cheeses can be classified by the kind of ripening agent and whether it ripens from inside or outside. Some examples include:

        i.            Bacteria ripened (from inside): Cheddar, Swiss, Gouda, Parmesan etc.

     ii.            Bacteria ripened (from outside): Limburger, Liederkranz etc.

   iii.            Mould ripened (from inside): Blue cheeses inc. Roquefort, Stilton etc.

   iv.            Mould ripened (from outside): Brie, Camembert, St. Andre etc.

      v.            Unripened: Cottage cream, Baker’s cheese etc.

Changes that take place during ripening:

a.      Lactose is converted to lactic acid.

b.      Proteins are broken down to simpler components–amino acids.

c.      Fats are converted to fatty acids.

d.      CO2 is formed that produces holes, as in Emmental cheese.

e.      Development of aroma/flavour.

f.       Change in colour.

g.      Change in texture–hard to soft–due to the action of bacteria or moulds (Brick – Bacteria, Stilton and Roquefort–Mould etc.).

Characteristics of Cheese

The characteristics of the cheese depend upon the following factors:

1.      Type of milk or milk fractions used (The percentage of fat present in the milk has an effect of the quality of the cheese produced. A low percentage of fat will produce a hard leathery type of cheese, whereas a high percentage of fat will produce a soft smoother cheese).

2.      Temperature (High gives hard, while low gives soft cheese).

3.      Acidity (Putrefactive bacteria, amount of lactic acid produced).

4.      Humidity (It controls the growth of moulds).

5.      Type of precipitation agent used in coagulating the milk.

6.      Pressure used to remove the moisture.

7.      Salt (Amount of salt added affects the growth of bacteria. It also acts as a preservative.)

8.      Time of ripening.

9.      Rennet will produce more elastic curd.

10. Light (whether exposed to sunlight or not).

11. Size of mold in which the cheese is made.

12. Type of microorganisms used.

Processed Cheese

Processed cheese is obtained by mixing green cheese with cured cheese of the same type or by blending different varieties of cheeses and then treating with heat and adding suitable emulsifying agent to it. Salt, acids, flavouring, colour etc. are also added and heated to approximately 65°C. When cheese is heated, further ripening is prevented. This processed cheese will be very mild. Processed cheese is a uniform product that doesn’t age or ripen like natural cheese. Thus, it keeps very well. It is usually very mild in flavour and has a gummy texture. Because of its melting quality and low price, it is often used in cooking.

The term “American Cheese” usually refers to processed cheese. Processed cheese food and processed cheese spread contain a lower percentage of cheese and more moisture than cheese. Modification of the same processed cheese without heating and pasteurizing, but simply ground and mixed with flavourings and seasonings, to a spreading consistency, is known as “cold pack” or “club cheese”. In this, further ripening will take place. Processed cheese is very common; since it can be sliced and blended easily with other ingredients of the recipe.

Cooking of Cheese

Cheese is a protein food and like all other proteins, it is toughened by heat easily. All cheese dishes should be cooked at low temperatures, whatever the dish is. Whenever possible, cheese should be melted in a double boiler or chaffing dish, rather than over direct heat. When cheese is melted, it is cooked. Overcooking will produce some toughening effect as cooking at too high heat. Grate or chop cheese finely and dilute with some kind of starchy food such as flour, breadcrumbs, macaroni etc. will help in cooking properly. Adding a small pinch of sodium bicarbonate will soften cheese and prevent stringiness as well as makes it more digestible.
Cook by moist heat, whenever possible, or at least see that there is some moisture included in the dish. Where and when possible, add cheese only at the last moment to prevent overcooking.

Selection of Cheese

The following points should be taken into consideration while selecting cheese:

1.      The rind of the cheese should not have mildew or fungi on it.

2.      There shouldn’t be an over-strong smell emanating from the cheese.

3.      Semi-hard, hard and blue-veined cheeses, when cut, should not appear dry.

4.      Soft and processed cheese, when cut, should not be watery; nor should be of a delicate creamy consistency.

Storage of Cheese

All cheeses should be eaten fresh and in their prime conditions. For this, they must be stored correctly so that they reach the customer in a good condition, with a full flavour. Cheeses should be wrapped in separate clean polythene bags to prevent their drying out, and then stored at a temperature of 5-10°C (40-50°F).

Before being served, the cheeses should be removed from the bags and placed in a room at normal temperature in order to have the full flavour maximized. Particular care must be taken for soft cheeses e.g. Brie, Camembert etc. as they can soon become over-ripe and unacceptable. Even hard and semi-hard cheese must be stored at low temperatures to avoid deterioration. Store cheese in their original wrapper, once they are opened and cut; cover with moist cloth or aluminium foil or plastic wrap to avoid drying out. The very hard cheeses like Parmesan and unprocessed cheeses don’t need to be refrigerated and may be kept in a clean, cool, dry storeroom. Blue cheeses require a lower temperature of around 4°C (38°F) and a higher relative humidity of 80%. Normally cheese should not be allowed to become dry and crumbly. Small pieces, weighing 1 pound or less of certain varieties like Brick, Camembert, Edam, Cheddar etc. can be frozen for 6-8 weeks. In general, the firmer and more aged the cheese, the longer it will keep.

Uses of Cheese

1.      As a cheese course in FCM for lunch or dinner. (Serve cheese at room temperature as only at room temperature will the full flavours develops).

2.      As a feature item on a cold buffet.

3.      As a cooking cheese:

a.      To add to a basic cream sauce to make a cheese sauce.

b.      To serve as an accompaniment to soups and farinaceous dishes.

c.      To serve sprinkled on dishes to be gratinated.

d.      To serve on toast e.g. grilled, Welsh rarebit etc.

e.      To include in salads, snacks etc. 

Cheese and Nutrition

Cheese is one of the most highly concentrated of all protein foods. It is also readily digested. Experiments have shown that 90-99% of all cheese is digested. It is also a complete protein. Since approximately 10 liters of fluid milk is required to make 1 kg of cheese, cheese contains many of the nutrients of milk in highly concentrated form – milk proteins, fats, fat soluble vitamins and minerals.

Whole milk cheese contains the same properties as milk. Certain cheese such as blue veined are made out of skim milk and are therefore less nutritious.
Normally cow’s milk is used to make cheese, but certain well known cheeses are made from goat’s milk. The texture of the cheese from goat’s milk differs slightly from that of cow’s milk. It is more crumbly. Sheep’s milk can also be used. The quality of cheese depends to a great extent on the breed and the condition of the animal and the fodder given to it. Cheshire cheese is said to owe its fine flavour to the wild radish, on which the cow feeds, and its special nature is due to the mineral in the soil. Cheshire cheese, therefore, can’t be made in any other place as Cheddar cheese can.
Certain cheeses develop a blue vein on maturing. This is sometimes a purely natural development, often sporadic and unpredictable. Sometimes, fresh cheese is inoculated with pieces of blue cheese to catch the mould by contact. In some cases, special bacilli are introduced. The mould is sometimes strengthened by brushing the cheese clean while the skin is soft, dipping it in whey and then rubbing it slightly with butter. This is done once a day for 10-20 days. Sometimes, cheese is pierced with a copper wire.

Some well known Cheese

       i.            Fresh cheese

Name of the cheese	Country
Cottage cheese	USA
Ricotta	Italy
Mozzarella	Italy
Cream cheese	No country specific

   ii.            Soft Cheese

Name of the cheese	Country
Brie	France
Camembert	France
Feta	Greece
Demi cel	France

iii.            Semi hard Cheese

Name of the cheese	Country
Cheddar	Britain
Edam	Holland
Emmenthal	Switzerland
Gouda	Holland
Gruyere	Switzerland

   iv.            Hard Cheese

Name of the cheese	Country
Parmesan	Italy
Pecorino	Italy

     v.            Blue vein Cheese

During coagulation or moulding step spores of fungus penicillium glaucum are added. This fungus gives the blue veining in the cheese.

Name of the cheese	Country
Danish blue	Denmark
Gorgonzola	Italy
Roquefort	France
Stilton	Britain

Glossary of Cheese terms

        i.            Acid, Acidity: A description of a pleasant tang; it can be a defect if too pronounced.

     ii.            Ammoniated: A term describing cheese smell of ammonia; a condition that afflicts the rinds of over-ripe cheese. A hint of ammonia is not necessarily objectionable.

   iii.        Annatto: A yellow-orange dye extracted from the seeds of a South American plant; used to colour such cheese as Cheddar, Edam etc.

   iv.            Bloomy rind: The white fleecy rind that develops on certain surface of ripened cheese like Brie, Camembert etc. It is formed by spraying of the surface of the cheese with spores of penicillium candidium, while it is curing. 

      v.            Chevres: The French term for Goat cheese.

   vi.            Gummy: A negative term used to describe an over-plastic texture, as well as over ripe rinds that have become sticky or gooey. Gumminess is undesirable in any context.

 vii.            Salty: Most cheeses have some degree of saltiness; those lacking in salt are said to be dull or flat. Pronounced saltiness is characteristic of some cheeses, but over saltiness is a defect.

viii.            Springy: A descriptive term for cheese with a resilient texture that springs back when gently pressed. Ripe or neatly ripe soft–ripened varieties should be springy.