9 Sept ., 1907.] Pasteurising Home Separator Cream. 525 



you are no doubt aware, destroys a large proportion of the living organisms 

 contained in milk or cream. This being effected, we have a fair field 

 in which to cultivate our pure lactic organisms which, so far as we at pre- 

 sent know, give to butter not only its best flavour and aroma, but its 

 lx?st keeping qualities. 



According to McKay and Larsen {Principles and Practice of Butter- 

 making), the Danish Government compels the pasteurisation of milk, 

 cream, and skim milk, with the object of checking the spread of disease, 

 in addition to securing uniformity in manufacture and better quality. Be- 

 fore going further, I wish to make myself understood on a matter that 

 may appear contradictory, viz., I believe that as good butter can be made 

 from home separator cream as from milk supply, and I unhesitatingly 

 assert that the greater proportion of inferior butter exported is the product 

 of the home separator. Under proper conditions, choice butter is made, 

 but under improper conditions and unhealthy competition the reverse is the 

 result. The efficient pasteurisation of this product removes taints of 

 various fodders, grasses, &c. ; in fact when cream is in anything like good 

 condition, there is no question but that an improvement can be made. Just 

 how far we can go I hope to be able to in some measure tO' show you, when 

 what I say is taken in conjunction with the various samples shown to-day 

 in the room. 



Coming to the practical results of the experiments, I have foimd that 

 it is possible to go much further in the pasteurisation of cream from an 

 acidity point of view than has been commonly supposed. Of course, the 

 fiesher the condition of cream, the better, but even sour cream, say of an 

 acidity of .55, can be pasteurised if over 40 per cent, fat, but to look 

 ior good results from cream of this acidity would, as a rule, be an error. 

 Before going further I want to draw your attention to one peculiarity 

 in connexion with jpasteurising home separator cream, and I think it 

 largely assists in the .success of the system. It is this: — -the heating of 

 cream to 160 degrees F., or over, considerably reduces the aciditv, as 

 shown by the titration test, and the higher the temperature and the more 

 acid the cream, the greater the variation. The explanation given is that 

 certain volatile acids are driven off in course of pasteurisation, and such 

 being the case, it is reasonable to suppose that if we can reduce cream 

 showing an acidity of .4 to .3 or .35 we can then successfully culti- 

 vate another lactic acid ferment which will assist in the manufacture of 

 a higher quality butter. 



The advantages of pasteurisation are: — 



1. Improved flavour. 



2. Improved texture. 



3. Improved price. 



4. A butter that can reasonably be expected to keep longer. 



5. The uniformity from day to day of a factory's output. 



6. Freedom from all, or nearly! all, disease germs. 



With regard to the advantages, the securing of uniformity from day 

 tc day, week to week, and prol)ably from factory to factory (that is if 

 \ve could systematise our methods and use the same cultures from factory 

 to factory and I believe we can), would enable us to produce a butter 

 which would hold its own in any market in the world. I want you to 

 recognise that the only difiicultv in the way of pasteurising four-fifths of 

 the supply received at country butter factories can be overcome by a little 

 ccr-operation between factory and supplier. 



