CHAP. vi. ACIDITY. 837 



Two points of considerable practical interest in the processes of 

 cheese-making are referred to by Mr. George Gibbons in his paper on 

 " Cheddar Cheese Making," both being due to the skill of Dr. F. T.Bond 

 of Gloucester. The first consists in a method of determining the 

 curdling point of milk that has been renneted, with a precision which 

 has not been hitherto attainable. It is founded upon the fact that 

 whilst a drop of ordinary milk, or even of milk that has been renneted 

 up to a certain stage, when allowed to fall gently on the surface of 

 water in a glass vessel, breaks up into rings, and ultimately diffuses 

 completely through the water, yet at a certain point in the development 

 of the curd, which Dr. Bond states has a definite relation to the period 

 when it becomes fit for cutting, the drop falls in a solid mass through 

 the water. This takes place so rapidly as to be distinctly evident 

 within one minute, and Dr. Bond claims that it gives a fixed point by 

 which the effect of rennet can be measured, with a delicacy that is 

 made greater than that of any other method hitherto in use. It is 

 clear that, if this be so, the cheese-maker has at his disposal a simple 

 method by which he can not only measure the strength of any given 

 sample of rennet, but can determine its effects on any given sample or 

 bulk of milk, with much more precision than hitherto, since the tests 

 usually employed for estimating the fitness of the curd for cutting, 

 though sufficient for this purpose, are not exact enough to allow of their 

 being used to measure the strength of rennet with any delicacy. 



The practical cheese-maker is recommended to study two papers by 

 Dr. Bond tjie one on " Acidity in Milk," the other on ' The Work of 

 Acidity in Cheese-making " in the " Journal of the Royal Agricultural 

 Society," vol. ii., 3rd series, 1891 ; also his paper on " Germs in the 

 Dairy" in the same Journal, vol. vii., 1896. 



The second contribution referred to, is a method of measuring the 

 acidity of milk, whey, &c., by the use of a standard solution of an alkali 

 combined with a colouring agent called an indicator. This method, 

 which is familiar in the chemical laboratory, has been adopted by Dr. 

 Bond for use in the dairy, in a way which makes it easily workable by 

 any intelligent person who will take a little trouble to master its 

 details. The control of acidity in cheese-making is a problem which 

 has puzzled many a maker, and if further investigation should confirm 

 the trustworthiness of this method and its applicability to general use, 

 there can be no doubt that the claim which Dr. Bond makes to have 

 added by these two contributions to the precision with which cheese- 

 making can be conducted, will be fully substantiated. 



A new kind of cheese, called " Oleomargarine Cheese," has been 

 recently invented in American dairies, the object being to economize 

 the skim-milk by using lard and other fat of animals to replace the 

 butter taken away in the skimming. The following description we 

 borrow from the pages of " The Farmer" : 



" This cheese is made from milk which has been set for cream and 

 skimmed, the cream being turned into butter, and oleomargarine added 

 to replace the material fat of the milk which has been taken off for 

 butter making. The object of adding oleomargarine is to so improve 



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