DAIRY FARMING 



Milk 



STERILISED MILK 



Sour Milk 

 versus Curds. 



Sterilising. 



Tainted Milk. 



Fermentation 



Germs 



killed. 



May be stored. 



Sale of 



Sterilised 



Milk. 



Modern 

 Traffic. 



Preserved 

 Milk (khir). 



Preparation of. 



that of lactic fermentation. This is the difference between sour milk and 

 curds. But milk and cream are soured by a large number of different forms 

 of bacteria which are communicated by the udders of the cow, the hands 

 of the milkers, the vessels into which milked, or simply through permeating 

 the atmosphere of the byre and the store-house. In many ways, therefore, 

 they may be conveyed to and absorbed by the milk when kept in open 

 vessels. The reader will find many highly important suggestions on this 

 subject in an article recently contributed by C. Bergtheil (Agri. Journ. 

 Ind., i., pt. iii., 233). " Milk and Cream," he observes, " are naturally ideal 

 media for the development of organisms, so much so that a sample of 

 cream ripe for butter-making has been found to contain as many as 

 1,500,000,000 bacteria per cubic centimetre, far more than those found in 

 sewage or any other natural material which has been examined. It, there- 

 fore, becomes a matter of great industrial importance to preserve milk 

 from harmful fermentations, particularly those occasioned by pathogenic 

 organisms." 



Sterilised Milk. The greatest cleanliness is imperatively necessary, for 

 even proximity to offensive smells will taint the milk. Some of the fermen- 

 tative germs immediately start growing and commence the souring process, 

 but these are instantly killed if subjected to a temperature of 50 to 75 0. ; 

 and should the milk also contain pathogenic germs (i.e the germs of such 

 diseases as typhoid fever) these will at the same time be destroyed. But 

 other fermentative germs are latent and little affected by such tempera- 

 tures as mentioned. In fact they are only killed either by continued boiling 

 for some hours or by repeated heating and cooling. While left in the cool 

 stage they are induced to assume the active condition, and are then killed 

 by the succeeding heating. Repeated heating will thus serve the same 

 purpose and more effectively (though more troublesome) than continued 

 boiling, and it avoids the undesirable changes in flavour caused by pro- 

 longed boiling. When once completely deprived of the germs of its 

 fermentation by heat, milk is described as sterilised or " pasteurised." 

 Even if not protected it will now remain wholesome for some considerable 

 time, but if kept in airtight vessels or bottles may be stored for months 

 without undergoing any injurious change. The success of the Agra, 

 Aligarh, Allahabad, Cawnpore, Darjeeling, Jabbalpur, Lucknow, Ootaca- 

 mund, Poona, etc., dairy farms in supplying sterilised milk is being 

 followed by many other institutions, so that supplies of good and safe 

 milk may be now had in all the larger towns. The trade is a prosperous 

 one with immense possibilities for the future. 



PRESERVED OR CONDENSED (DESICCATED) MILK. This is made by boil- 

 ing fresh (whole) milk, to which sugar has been added, until it attains the 

 consistence of syrup. This is called khir (khyir) and in some parts of India 

 rabbri, but sugar is not always added. Of Bengal districts, Tippera is spoken 

 of as producing khir of special quality. Sen, discussing Dacca, says, " The 

 flavour of this preparation of milk depends on (a) the quantity of milk boiled at 

 a time, (b) the care with which the milk is stirred at the time of boiling, and (c) 

 the nature of the heat applied, (a) To obtain khir as white as possible, and 

 possessed of the best flavour, not more than half a seer of milk should be boiled 

 at a time. (6) All the time the milk is boiling it should be stirred with a wooden 

 rod. Some prefer to stir with a number of rods, (c) A strong and steady heat 

 should be applied. Tamarind wood is considered the best fuel for this purpose. 

 Khir of an inferior quality is sometimes made from fresh butter-milk." 

 Banerjei remarks, " In order to get the khir or thickened milk of a fine white 

 colour, a little flour is added. In private houses arrowroot is used instead. 

 When thick enough it is removed and allowed to cool, when it is ready for sale." 



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