Cook's Encyclopaedia

by Tom Stobart

  On the other hand, the effect of extreme cold is merely to prevent the multiplication of organisms rather than to kill them. For instance, the typhoid germ can live up to a week in ice-cream, and some organisms have been known to survive the shattering cold of liquid hydrogen at -252°C (-421°F). Deep freezing does not sterilize food.

  For many micro-organisms, the *pH is critical. Yeasts prefer acid conditions (pH 3.0-6.0) and so do moulds, although some can be found to thrive at almost anything from pH 1.0 to pH 11.0. On the other hand most bacteria prefer more or less neutral conditions (pH 6.5-8.0) and very few (and certainly not the harmful ones) will grow or even survive for long in acidity below pH 4.0 (or in really alkaline conditions over pH 9.0).You can get an idea of what this means from the fact that lemon juice is about pH 2.3. Even sour milk, which is pH 4.4, is inimical to many bacteria.

  However, the activity of acids in stopping bacteria from growing is not entirely dependent on the pH. Some acids are more toxic to micro-organisms than others and, therefore, more preservative. lf we gave sulphuric acid an effectiveness of one, then the relative effectiveness of the other commonly-used *preservatives would be as follows: tartaric acid 3; hydrochloric acid 6; sulphurous acid (sulphur dioxide in water) 9; citric acid 13; formic acid 16; benzoic acid 21 and salicylic acid 33. Chemicals which either stop micro-organisms from multiplying or kill them are *disinfectants.

  Ultra-violet light will kill micro-organisms, although some are more susceptible than others. There is ultra-violet in sunlight, and ultra-violet lamps are sometimes installed in operating theatres, factories and food stores. If they are switched on when the rooms are not being used, they serve to reduce the number of organisms in the air.

  MILK has been a source of food and drink since early herdsmen first learned to take milk from their animals. However, milk and milk products (such as butter and cheese) are less common in China (though butter is popular in Tibet), and they were quite unknown to the ancient civilizations of America. Milk today is normally cow’s milk, but in ancient times there were no dairy cows, and oxen were beasts of burden. Milk mainly came from sheep, goats, asses and horses. Camels were domesticated much later – their milk is purgative but is used by Bedouin tribes. (Pigs cannot be induced to give milk.)

  Milk evolved as a complete diet for suckling mammals, but is a very good food for children and adults. It contains good quality protein, digestible fat and a sugar as well as minerals and vitamins; composition varies enormously from species to species. The main constituent of milk is water (87% by weight) in which are dissolved lactose (milk sugar), an albumin, citrates and chlorides of sodium and potassium, and vitamins B1, B2, and C. Partly in solution and partly in suspension are phosphates of calcium and magnesium while caseinogen, the chief protein, is in colloidal suspension. The minute fat droplets contain the fat-soluble vitamins A and D. The yellow colour of the fat in summer milk in some breeds is caused by carotene which is a precursor of vitamin A, and comes from the grass and herbs the animal eats. The *pH value of fresh cow milk lies between 6.5 and 6.8 (i.e. it is very slightly acid) but is most commonly about 6.6. Milk is an ideal food for many bacteria. Many of them can convert the lactose into lactic acid, making the milk gradually go sour. Souring can first be detected by taste at around pH 6.2; milk that is slightly more sour may curdle when heated. You should note that it is particularly liable to do so when given a sudden heat shock, for example by being poured into hot tea; when it is treated more gently (and the tea is gradually poured into the milk), it may not do so.

  When milk curdles, the main protein, which has been held in colloidal suspension, is precipitated as casein. Heat encourages curdling, as also does salt. This explains why some soups and sauces need careful handling to avoid curdling, and why they may need stabilizers such as the starch gel used in white sauces. Milk may curdle either with or without setting to a clabber. Bacterial action, mild acids and rennet will cause milk to clabber, but strong acidity and salts like alum will curdle milk without producing a clabber. Acid curdling takes place when the pH reaches about 4.8, but happens at higher pH values (i.e. lower acidities) when the milk is heated. Raw milk usually goes sour if it is kept at room temperature, but pasteurized milk and boiled milk in which the acid-forming bacteria have been destroyed, usually develop a bitter taste and unpleasant flavours.

  The composition of milk varies appreciably not just between species but between different breeds of the same species, between animals in the same breed and even in each individual animal around the year. The figures given in the table are average ones.

  Composition of milks of various mammals

  Several interesting points emerge from these figures. Cow’s milk is richer in protein and contains less sugar than human milk; some adjustment is advisable when cow’s milk is used to feed babies. Mare’s milk is high in milk sugar, in Asia, it is fermented to make alcoholic drinks such as *koumiss. Camel’s milk, which is rather low in fat, has very small fat globules and cannot readily be churned to make butter. Buffalo milk, on the other hand, is very rich in fat and protein, and so makes splendid cheese and butter.

  In an emergency, a suitable milk for feeding babies can be made up of one part water to one part cow’s milk, with a level teaspoon of sugar per 100 cc (3½ oz) of feed, provided it is heated nearly to boiling and then cooled to blood heat. Feeding of cow’s milk to babies can sometimes cause trouble – a form of allergy to cow’s milk is thought to be a possible cause of ‘cot deaths’ in babies. If you have to feed other suckling animals, you should find out the composition of milk in the species concerned, and cow milk should then be adjusted with cream, water, and sugar. Having brought up many animals, from wolves to gazelles and wild rabbits, on a bottle, I know that care over the composition of the milk makes all the difference to their survival.

  Grades of milk in Britain are distinguished by colour-coded bottle tops, although much milk is now sold in cartons or even polythene bags on which the description of the contents can be printed. The colour code for bottle tops is as follows:

  Raw, untreated Green top

  Pasteurized Silver top

  Homogenized Red top

  Sterilized Crown cap or blue foil top

  UHT Pink top (date stamped)

  Channel Islands Green top with gold stripe if raw or bottled on farm. Gold top if pasteurized

  Only TB-free or TT milk is now allowed to be sold in Britain.

  Channel Islands milk comes from Jersey or Guernsey cows, small animals which produce especially rich milk – by law, this must contain a minimum of 4% butter fat.

  Pasteurized milk has been heated to 71°C (160°F) for 15 seconds and quickly cooled to 10°C (50°F).It keeps for 1-2 days in a cold larder, 2-3 days in the refrigerator.

  Homogenized milk has been mechanically treated – *homogenized – so that the cream no longer rises when the milk is left to stand. The even nature of the product is an advantage in the catering business, but not to the cook.

  Sterilized milk is homogenized and sterilized in bottles at 108-115°C (226-239°F) for 20-30 minutes. Now usually has a preliminary high temperature treatment. Unopened keeps fresh for at least a week and often for several weeks without refrigeration.

  UHT milk or long life milk. UHT means Ultra High Temperature: homogenized milk is heated to 132°C (270°F) for 1-2 seconds, then rapidly cooled and packed in sterile conditions. It will keep for several months unopened, but behaves like other milk once it has been opened.

  Skimmed milk has had practically all the fat removed by separation. It is often no cheaper than full cream milk, but is much used by people on diets or with a cholesterol problem.

  Dried milk, powdered milk, or dehydrated milk. Spray-dried milk is made by spraying whole or skimmed milk into a large chamber of hot dry air, the powder which is formed falls to the bottom of the chamber. It is almost 100% soluble in water. Roller-dried milk is made by putting a film of concentrated milk on a heated steel roller and scraping it off when it has dri
ed. Reconstituted roller dried milk contains small insoluble particles, which fall to the bottom. Milk powder, whether whole or skimmed, contains about 4% moisture. Because of changes which take place on heating and exposure to the air, it is nutritionally slightly inferior to fresh milk. To reconstitute it, mix it to a thin paste with a little cold water, and then dilute with hot water. 10 parts water to one part of dried milk is a usual mixture. The fat – 26% in full-cream powdered milk – becomes partly oxidized in drying; this produces the characteristic, not very nice, flavour of dried milk. Skimmed milk powder, with very little fat (1%) tastes better. At a pinch, melted butter, even oil or margarine, can be emulsified in a blender with water and skimmed milk powder, and the result is better flavoured than that of reconstituted whole milk powder.

  Frozen milk. If milk is frozen slowly, it will keep but does not return to normal when thawed. It can be used only for cooking. If milk is held just above freezing, its life is lengthened, but after a week, it can begin to putrefy without souring, and poisons can accumulate, which make it dangerous. Do not keep milk refrigerated for over ten days (get sterilized or UHT milk as a standby). UHT milk can be frozen and drunk as milk after it has thawed (which can be useful in the tropics).

  Milk products include *cream, *evaporated milk *condensed milk, *buttermilk, *yoghurt and *sour milk products.

  Milk substitutes are the filled milks and non-dairy creamers which are made with skim milk solids, fats or oils (such as lard or hydrogenated vegetable oils), emulsifiers and anti-oxidants. Those made with vegetable oils may have a higher unsaturated fatty acid content than ordinary milk and no cholesterol.

  Vegetable milk can be the milky sap of plants such as that of Galactodendron, which is used in Colombia as a drink and in cooking; it can be an emulsion made with oil-rich nuts, such as milk of almonds or the coconut milk and cream which are used in Indian cooking. It can also be made from soya beans – soya milk.

  [Milk – French: lait German: Milch Italian: latte Spanish: leche]

  MILK SUGAR. See lactose.

  MILLE FIORE. See liqueurs and cordials.

  MILLET and SORGHUM. Various grasses, with small edible grains, are known as millets, a word derived from the Latin milium, the common millet which was grown by the Romans. Millets vary greatly in the quality of their grain, and none is as good as wheat, but they are grown because they produce a crop, often a good crop, even in the poorest soils, both waterlogged and in drought. Some, like the Bulrush millet, make it just possible for people to exist in areas of extreme aridity and heat.

  Most people in Britain see millet only as bird seed – sometimes the whole ears are hung up in cages. The seeds will often sprout and grow on waste dumps – and even ripen in a good year. In the US, millets are grown extensively as animal feed, and the sweet variety is used for sorghum syrup. Otherwise, millets are foods of the world’s poor – they are rough, but healthy. The common millet contains about 10-13% protein and about 4% oil, although millets are considered as carbohydrate cereals. Millets are quite commonly fermented and made into beers, both the crude ‘native beers’, and more sophisticated brews, in which case the grain is malted. Millets do not make gourmet foods; they are mostly ground and boiled into porridges or made into unleavened bread. Recipes for other millet dishes are few, but one for ragi (finger millet) dosas is offered as an example.

  Ragi Dosas

  Dosas might be described as South-Indian pancakes, usually made of a fermented batter of soaked and pounded black *dal and rice (though modern short cuts use rice flour). Dosas are often rolled and stuffed with vegetable curry as a breakfast dish. Ragi dosas are not so good to look at, but are still delicious.

  Take 2½ cups of ground finger millet, add a teaspoon of salt, and mix with water into a stiff paste. Soak 7½ tablespoons of black gram dal for an hour, then put it in the liquidizer and grind it to a thin, frothy paste. Mix the two pastes together into a batter of thick pouring consistency. Cook by putting a large spoonful on to a hot iron girdle or plate (which has been smeared with a little oil) and spreading it quickly into a thin, round platesized pancake with the back of a spoon. When the underside is golden brown, turn it over and cook the other side rather more lightly. Put a spoon of filling on it and roll it up, or eat it with butter and honey (and some fresh coriander-green chilli chutney for perfection).

  Barnyard millet or bharti (Echinochloa crusgalli) which grows as a naturalized weed in Britain and the US, is grown as a crop in the Orient, but mainly for fodder. The Japanese millet or sanwa (Echinochloa frumenlacea) and the smaller shama millet (Echinochloa colona) are eaten as a porridge or with rice.

  Bulrush millet, bajra, cattail, or reedmace (Pennisetum typhoideum) is a tropical millet that is important in India, Nigeria and the Sudan; it grows quickly and stands drought. Under the name of bajra, it is one of the most important Indian millets (although it is native to Africa) and is used by the poor to make flour and unleavened bread. It gets its popular name because its head is like that of reedmace, commonly called bulrush. It is not to be confused with foxtail millet, which is more hairy. Its white-seeded variety is known as pearl millet.

  Common millet, broom-corn, proso, Indian millet, or Hog-millet (US), Panicum miliaceum, is a temperate millet, which is grown in Russia, China, Japan, North America and southern Europe. In the US and southern Europe, it is rarely used today as human food – for long it has been grown only for chickens and other livestock – but its use as human food is prehistoric, and it makes good unleavened bread. The grain of common millet is oval and varies from white to straw-coloured, red or brown. It is often used as a bird seed.

  Finger millet or ragi (Eleusine coracana) is of Indian origin. Although it grows in many forms, it gets its name from a common type in which the head looks like five stubby, outwardly-curved fingers. It is a staple in India, not only because it can grow in poor soils but also because it gives a heavy yield and the grain stores particularly well. In Africa, it is grown from Rhodesia to the Sudan. Coarse when compared to wheat, it has a good taste and is made into breads and other cereal preparations. It is also fermented into beers and is even malted.

  Foxtail millet, German millet, Hungarian millet, Italian millet, or Siberian millet (Setaria italica) is a warm temperate millet, which came originally from the Orient. It was used in China in 2700 BC, and also by the Lake Dwellers in prehistoric Europe. It is still reaped in Russia to a considerable extent for beer. The grain may be white, yellow, red, brown or even black. It is grown in southern Europe and the US for chicken food and fodder. It can be used boiled or parched as human food but is not particularly nice.

  Hungry rice (Digitaria exilis) is a grain that is locally important in dry West Africa.

  Job’s tears (Ciox lachryma-jobi) is not really a millet, as the seeds are large. A tropical and subtropical crop, native to India, it can also be found growing in southern Europe as an ornamental plant. The pearly fruits are used for necklaces, and it is claimed that the seeds contain more protein than any other cereal. This is eaten mostly in South East Asia and the Philippines (where it is called adley). It is sometimes used medicinally, as well as for sustenance.

  Little millet (Panicum miliare) is like the common millet but smaller. It gives a moderate yield on very poor soils. In India, it is known as the poor man’s crop (which there means really poor).

  Sorghum (Sorghum vulgare) is often a tropical crop, and in India and Africa is a staple for the poor. Varieties differ considerably and may be grouped into categories based on their uses as well as on their characteristics.

  Sweet sorghum or Sugar sorghum (var. saccharatum) has a stem rich in sugars and is crushed to obtain the juice which is boiled down and evaporated in shallow pans to make sorghum syrup (which is a thinner and sourer equivalent of molasses). Millions of gallons of this are used in cooking in the US every year, but elsewhere sorghum syrup is less known.

  Durra or Great millet is called jawor in India. It is a staple food for millions around the world and i
s one of the world’s most vital crops. There are two main types: white-grained sorghum, which is favoured for bread, and red-grained, which is bitter and mainly used for brewing beer. In India, jowar is ground daily in most poor homes and used to make flat unleavened bread which is not so refined as the chapattis or rotis made from wheat flour (atta), but which makes a satisfying meal. This, not wheat or rice, is the main food in the dry areas of the subcontinent.

  Kaffir corn (var. caffrorum) and milo (var. subglabrescens) are of African origin and are essentially the same from the gastronomic, if not the cultivator’s, point of view, as is the Chinese kaoliang.

  Teff (Eragrostis abyssinica) is the most widely grown cereal in Ethiopia. It is ground to form the basis of the fermented flat bread called injura, which is eaten with the hot curry-like stew called wot. lnjura is full of bubbles and has the texture of tripe. The taste is sour. It is rather nice, once you are used to it.

  [Millet – French: millet German: Hirse Italian: miglio Spanish: mijo]

  MILLING is reducing to a powder or paste. The most primitive method is pounding, and since such creatures as different as otters and vultures have learned to use stones as tools, it is probable that man learned to pound grain even before he could grow it. Today, in the more primitive tropical countries, you can still see grain being pounded in large mortars hollowed out of stones or tree trunks. Primitive grinding with stones, the precursor of milling, is done daily by countless Indians when they grind their fresh curry spices with a roller on a stone slab.

  A more sophisticated grinder is the quern, which is typically constructed of two round stones, the top one revolving on a peg set in the lower. The peg must be shaped to allow grain to fall round it down between the stones. The top stone is rotated by hand. Portable querns are still used today – for instance, by the nomadic tribes in Baluchistan – and were common enough everywhere in the past, and there were even special mini-querns for mustard.