8 9 



The Miller people and D. H. Burrell & Co. now also make 

 regenerative pasteurizers. 



Personally, I prefer to heat the skim-milk and the cream 

 separately. I have found that when the new milk showed an 

 acidity of 14 cc by Mann's Test, the cream would only show 9 or 

 10 cc, partly on account of the greater proportion of fat and 

 partly, I presume, because many acid producing bacteria are sent 

 to the wall of the separator in the slime, and partly because there 

 is less serum in proportion to the fat. 



But another reason is that at but few creameries can we 

 afford to cool the skim-milk properly, and hence, I deem it better 

 not to do it partially, but rather return the skim-milk real hot, 

 hot enough to pasteurize the little milk left in the cans. 



Prof. Farrington draws the line of 0.2 per cent acidity, or 

 about ii cc by Mann's Test for pasteurizing for commercial pur- 

 poses, and I feel inclined to draw a line not far from that even 

 for buttermaking. It is a fact to be remembered that all heaters 

 hitherto used will coat (and thus lose efficiency) just in propor- 

 tion to the acidity of the milk and that the cooked flavor also in- 

 creases with the original acidity. 



Whatever system is used, a quick and intense cooling is abso- 

 lutely necessary if a cooked flavor is to be avoided. For this pur- 

 pose, the "Star," (Fig. 3), the "DeLaval" or the "Smith" Cooler 

 (Fig. 81), are all efficient and good. And so are the direct ex- 

 pansion 'coils or brine coolers, used in 

 connection with refrigerator machinery. 

 But all these coolers require a con- 

 siderable drop, and if this is to be 

 avoided, I know of no better coolers 

 than the improved "Baer," shown in 

 Fig. 34, and arranged zig-zag, one un- 

 der the other. These coolers may be 

 made any length and three 10 feet 

 lengths will only require a total drop 

 of i foot, and the first heat can be tak- 

 en out by using the condensing water 

 from the refrigerator (say at about 78 

 or 80 deg.) in the first length, ordinary 

 is. sit water (say 50 to 55 deg.) in the next, 



and, if desired to cool very low, brine in the last length which 



