THE PREPARATION AND USE OF LIME AS A NEUTRALIZER 197 



This is a general solution which applies to any weight of 

 cream. 



Where lime is completely slaked or hydrated it takes a^ little 

 over 32 per cent more of it than of quicklime (74 pounds as against 

 56 pounds) to make the same strength of mixture. As the mix- 

 ture upon which the table (p. 196) is based contains 12.5 pounds of 

 quicklime to 10 gallons, it would require 16.5 pounds of hydrated 

 lime to 10 gallons to make the same strength of mixture. If 

 the lime is only partially slaked it will, of course, take less than 

 16.5 pounds. 



The quantities of lime indicated for making the mixture are 

 theoretically correct, but the individual user will be obliged to 

 determine by test whether the mixture is right in strength for his 

 cream. It may be necessary to use a little more or a little less 

 lime than indicated, in making the mixture, probably a little less 

 if any change has to be made. If necessary, a slight change may 

 be made in the strength of the mixture to avoid changing the 

 table. 



In investigations conducted by Hunziker, in which he used 

 the strength and quantity of lime mixture supposed to be suf- 

 ficient to reduce the acidity of the cream to .25 per cent, he 

 secured the following average results: 



Per Cent 



Initial acidity of cream 75 



Acidity three hrs. after neutralizing, pasteurizing and cooling. . 33 



In other words, whereas the acidity should have been reduced 

 by .50 per cent (.75 .25) it was only reduced by .42 per cent 

 (75 --33)- T m ' s means that (33-25)^5 or A = i6 per cent 

 of the neutralizer was not used, or that this mixture would need 

 to be strengthened to the extent of the addition of 15 to 20 per 

 cent more lime. 



On the other hand, Hunziker found that when enough lime 

 mixture was added to a pure lactic acid solution to theoretically 

 reduce its acidity to .25 per cent it actually did reduce it to this 

 point. The conclusion he reached, through his investigations, 

 was that some of the lime added to cream attaches itself to the 



