A myriad of national cheeses from milk

Posted in Animals, Farming on Wednesday, 28 September 2011

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This edited article about cheese originally appeared in Look and Learn issue number 826 published on 12 November 1977.

milking, picture, image, illustration

One of the first milking machines was invented in the nineteenth century

A walk around any large supermarket brings to view a huge and fascinating variety of different milk products. Cream, butter, ice cream, buttermilk, condensed milk (sweetened and unsweetened), milk powders, yoghurt and fermented milks, separated and skimmed milks – and cheese.

Cheese comes in all shapes and sizes, and its colouring can vary from creamy white to electric blue. The taste of one type of cheese can be completely different from others: it may be mild, or it may be very distinctive. Some cheese may even be totally unpleasant to some palates, for many types are so strong that only experienced cheese connoisseurs enjoy them.

Just how is this most versatile of milk products made, and how many types are to be found across the world? The methods vary from country to country, but the same basic principles always apply.

As for the number of different types? We could quite easily fill a book in trying to cover that particular subject.

The basic ingredient for making any kind of cheese is pure milk. It may well be that the milk used to make a certain variety of cheese has come from a goat, or from some other animal. Cow’s milk, though, is the most commonly used in the types of cheese that we find on our own tables.

Strains of a substance called lactic acid are implanted into fresh pasteurized milk and this leads to the growth of a mild bacteria. In fact, cheese in its basic form, is really no more than a solid, stale variety of milk. The germs which are deliberately introduced into the milk cause a carefully limited degree of impurity to grow, in order to bring about what is known as the isoelectric point. This is the point where the cheese starts to solidify – to curdle – and is the secret behind successful cheese-making. If the process is taken too far beyond the iso-electric point, it will turn bad and go “off”, yet if too little lactic acid is introduced, the end result will just be a rather smelly form of stale milk. The whole process, therefore, has to be carefully controlled.

The differences in cheese produced in different places are due to varying compositions and the types of milk used, variations in the process and differences in the types of bacteria used. These different varieties of cheese can largely be classified into two main groups – hard and soft. Hard cheeses have most of the whey (the watery substances which remain after curdling) removed, while in soft cheeses a considerable amount remains.

Let us take, as an example, the making of Cheddar cheese, easily the most widely-used variety in this country. This cheese has a mellow, slightly nutty flavour, which improves with keeping, rather like a good wine. First of all, a prepared culture of lactic acid bacteria, known as the “starter”, is added to pasteurized milk in a cheese vat. The milk is heated up to a temperature of 30 degrees C and its lactic acid concentration allowed to reach 0.2 per cent.

A substance called rennet is added at this stage and, ideally, the final “mixing” process, called coagulation, is reached in about 20 minutes, giving a curd-like solid junket. The curd is ready for cutting when it is solid enough to break over one’s finger.

Cutting is carried out using two “American” knives, horizontal and vertical bladed. These are passed through the curd, cutting it into pea-sized cubes. The curd is then stirred continuously during a scalding period of one hour. During this time, the contents of the vat reach a temperature of between 36-40.5 degrees C. This scalding helps to expel the whey from the curd and to obtain the required texture: all-important if the cheese is to be enjoyed at the meal-table afterwards.

For the next stage in the cheese-making process, the whey is run off and the curd is cut into 20 cm.-square blocks. These are then piled on each side of the vat and are left to drain completely. The blocks of curd are now milled or cut into chips about the size of a walnut, and salt is added in small quantities.

The salted curd is packed into moulds packed with cloth, which are traditionally cylindrical, although square cheeses are now made, which require less storage space and need no turning during ripening. The moulded cheeses are then pressed for a short time to drive out the remaining whey, and are sprayed, shortly after, with hot water and left under pressure for 24 hours. The hot water sprayed on gives rise to a thin, hard rind, necessary if the cheese is to keep satisfactorily.

Finally, with the cheese-making process almost completed, ripening in a well-aired room, at temperatures of 15-25 degrees C, takes place. The flavour of the cheese is developed during this phase, by the changes bought about by the bacteria which remain active. As the ripening process goes on, the cheeses are turned daily at first, and then less frequently, and are rubbed well with a special oil. The ripening of the cheese is the most important part of its preparation, and requires skill and care if the end product is not to be spoilt.

The food value of cheese is particularly high: indeed there is no foodstuff ordinarily available which even equals it, in respect both of concentration and of variety of nutritional ingredients. An average whole milk cheese consists of protein, fat and water, in the approximate proportion 2:3:3, and there are also appreciable quantities of health-giving minerals, among which calcium is the most abundant.

Bel Paese, Bresse Bleu, Brie and Gouda: these are just a few of the hundreds of different types of cheese produced around the world. “Gorgonzola” is the name given to the well-known (and heavily scented) blue-veined Italian cheese. Produced as far from our shores are Emmental and Gruyere: two fine varieties of Swiss cheese, having a distinctly strong flavour and bearing a close resemblance to the holed cheeses seen in the famous cat-and-mouse cartoons!

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