200 MILK AND DAIRY PRODUCTS PART 



Buddised milk has not come into general use, and the reason 

 may be that it is difficult to gauge the right amount of 

 hydrogen peroxide to be added. Different milks possess very 

 varying powers of decomposing hydrogen peroxide, no doubt 

 due to the amount of catalase which they contain. If more 

 hydrogen peroxide is added than can be decomposed, the milk 

 acquires a characteristically unpleasant taste, whilst a deficiency 

 only results in a shorter or longer " stupefaction " of the bacteria. 

 After some hours they become active again and spoil the milk. 

 Further, also, when too little hydrogen peroxide has been 

 added, the lactic acid bacteria may have been killed, but not 

 the peptonising and putrefaction organisms, so that in the 

 consumption of the milk there is the same danger as was seen 

 to exist with pasteurised milk (p. 199). 



It must also be clearly noted that the addition of any 

 preservative to milk, even when of such a harmless nature as 

 hydrogen peroxide, which splits up into water and oxygen, acts 

 in opposition to the efforts which are now so strenuously 

 and properly being made to ensure a supply of milk that 

 shall be as free as possible from bacteria. The only preservatives 

 that ought to be allowed are a high degree of cleanliness and 

 a rapid and thorough cooling of the milk. If such preservatives 

 as formalin and hydrogen peroxide are put into the hands 

 of milk producers and milk dealers, the proper hygienic 

 treatment of the milk during and after milking will be very 

 liable to be neglected. 



Condensed milk was first prepared by the American, Gail 

 Borden, in 1856. The principle of the preparation has 

 hardly undergone any change since then, and briefly is as 

 follows : 



Good fresh milk (considerable importance is attached to the 

 quality of the milk) is evaporated down in a vacuum pan, 

 similar to those used in a sugar factory, at a temperature 

 of 40-50 C. until the volume is reduced to a third or a 

 quarter of the original. The evaporation must be conducted 

 with great care, for otherwise the milk sugar crystallises out and 

 this causes the condensed milk to feel " sandy " on the tongue. 

 Condensed milk is made either with or without the addition of 

 cane sugar; when it is added about 10-12 per cent, of the weight 

 of the milk is taken. When the evaporation of the milk is at 

 an end the yellowish-white syrup is sealed up in tins which 



