R. K. Robinson

Selected cheese recipes

As already stated, it is prudent for a cheesemaker attempting the manufacture of unfamiliar varieties of cheese to first gain experience with that variety. Although a recipe is a guide to the practice of cheesemaking there are often sound reasons, sometimes local, for certain deviations from written guides. These reasons may not apply elsewhere.

Coagulants and precipitants

As already mentioned in Chapter 1, the early tribes of the Middle East used natural fermentations to produce fermented milks (yoghurt, koumis, kefir). It was, therefore, a short step to the use of naturally soured milks or sour whey as a ferment to produce the acid necessary to give a precipitation of the casein which enclosed the other constituents of the milk. Separation of liquid serum (whey) from this coagulated milk leaves a curd (i.e. a soft lactic cheese).

Tests for acidity and chemical analysis in process control

The biological, biochemical and physical changes which take place from the time milk leaves the udder until the cheese is finally ripe are often controlled or aided by the pH (hydrogen ion concentration) of the liquid or curd at that time. The delicate physical equilibrium between the constituents of milk due to ionization of components, the binding of protons and the dispersion of salts and proteins between the phases, leads to a buffering capacity in respect of pH change The acid—base equilibrium of the milk, whey or curd is a useful parameter for control of the processing of cheese.

Membrane filtration of milk and whey

The term ‘osmosis’ is used to describe the spontaneous flow of water from a less concentrated to a more concentrated solution when the two solutions are separated by a suitable membrane.

Bacteriology in relation to cheesemaking

The fermentation of carbohydrates and nitrogenous compounds in milk or curd by micro-organisms is a basic activity in the cheese process. For this reason it is useful to examine, very briefly, the metabolism of the bacterial cell in order to understand some of the activities of bacteria in the cheese process, although the cheesemaker is concerned not only with the activities of the living cell, but also with the release of cell contents, particularly enzymes, on its death.

Cheese faults and cheese grading

Cracks may develop in the rinds of cheeses that are not waxed or shrink-wrapped, and such openings may allow moulds to penetrate into the curds or cheese flies (Piophila casei) to lay eggs in the cracks so that the cheese becomes infested with maggots. Such cracks, which may be deep or exist as a network of small superficial lines, are caused by the curd shrinking during maturation, especially at low humidities (60% RH). The cause of such problems may be: the moisture or acidity of the curd is too high at pressing the curd is too cool (below 24°C) at pressing, so that the separate particles do not link up and cracks develop there is a lack of tat in the milk, especially in spring, with the result that the curd does not hold sufficient moisture and the hard curd may crack.

Cheese whey and its uses

Cheesemaking by traditional or modern methods inevitably produces a large quantity of whey (approximately 83% of the volume of milk used), and it is difficult to divorce whey disposal from cheese technology, because the disposal of whey is a major industrial consideration. In addition, whey contains valuable nutrients, i.e. whey proteins, lactose and minerals, and hence it should not be thrown away as waste, but should be used for stock and human nutrition.

Mechanization of cheesemaking

Attempts at the mechanization of cheesemaking operations began in earnest in the 19th Century. The first of the irksome tasks performed by the cheese-maker was the stirring of curds in the vat, while the turning of cheese on the shelves in the store was a task assigned to farm labourers. Small circular vats were convenient for installation of a revolving paddle for stirring the curd, and the Edam and Emmental cheesemakers were amongst the first to benefit.

Importance of cheese as a food

According to the FAO (1994), the worldwide production of all types of cheese rose from 5 934 000 tonnes in 1963 to 14 880 089 tonnes in 1993, and Table 2.1 shows the production of cheese in various areas of the world. The precision of the figures is, of course, open to debate, because there is no doubt that much locally made cheese in countries from South America and elsewhere does not enter the statistics. Similarly, there are cheeses from the industrialized countries that have more in common with dairy desserts than traditional products and, again, their position in the production figures for any given country may be in doubt. Nevertheless, the general view is that the volume of cheese produced across the world will continue to increase and that, with fermented milks, will become the major outlet for liquid milk not required for direct consumption. However, the annual increase in cheese production depends not only on the availability of milk, but also on the ability of the industry to sell the cheese, bearing in mind the impact of such factors as: the prevailing economic conditions, market changes due to eating habits (e.g. rise in the number of vegetarians), availability of alternative high-protein foods (e.g. meat or fish), levels of disposable income and any changes in barriers to trade (e.g. the introduction of Certificates of Origin for certain varieties of cheese). In addition, milk production quotas of the type imposed by the European Union can have a devastating impact, and it is generally agreed that they have adversely affected the volumes of dairy produce, including cheese, manufactured in a number of EU countries. Table 2.1 Some guideline figures for the production of cheese (all types) in different regions of the world during 1993 (thousand tones) Africa 495 Egypt South Africa 333 38 North America 3861 USA Canada 3385 305 South America 613 Argentina Brazil 330 60 Asia 873 Iran China 200 164 Oceania 873 Australia New Zealand 233 190 Eastern Europe Russian Fed. 708 Western Europe France Iraly The Nerherlands UK Denmark Greece Ireland Bel-Lux 1562 919 647 362 288 210 91 7 Total world production 14 880 Source:(FAO Production Yearbook,1994.)

Preparation of cheese milks

Milk storage is an important feature of cheesemaking. It is a necessary part of the cheesemaking routine to ensure that tanks and ancillary equipment be used effectively and kept clean. Except for the smallest quantities of milk or those milks used for cheese while still warm, most milks are subject to storage for longer or shorter times; even during transportation, milk is accepted as being in storage. With the advent of larger cheese factories, and especially those concerned with collecting milk ex-farm in bulk cold tanks, the storage of milk has become a most important stage in the process. The advent of a 5-day working week for creamery workers makes the storage of milk even more important.