17 



The box of butter put into cold-storage held its flavor much better 

 than did the prints which were exposed to a high temperature for 38 days. 



Preservatives for Cream, 



It has been recommended that patrons of cream-gathering creameries 

 txi supplied with a preservative to place in the cream to prevent its sour- 

 ing before delivery. A few trials were made of a special cream preserva- 

 tive, between July 16th and 25th. For these trials a large test tube was 

 used having a cotton plug in the open end. The samples were kept at 

 a temperature of 60 to 70 degrees F. in an ordinary room. The amount 

 of preservative was as nearly as possible the proportion as recommended 

 by the manufacturers. The following are some of the results : 



July 18, 11.30 a.m. Pasteurized and cooled skim-milk placed in a 

 added. Cream thick and sour 11 a.m., July 18th. 



July 18, 11.30 a.m. Pasteurized and cooled skim-milk placed in a 

 test tube and preservative added. Sample sour and thick 10 a.m. on the 

 20th. 



July 20, 10 a.m. Skim-milk from separator which had not been 

 pasteurized or cooled was added to test tube. Milk was ^t;parated at a 

 temperature of 90 degrees F. Extra amount of preservative added. 9 

 a.m. on the 21st, sample sweet but had a bad flavor. On the 23rd at 3 

 p.m. sample slightly sour. Flavor not so bad as on the 21st. On July 

 25th, flavor improved and acid developed slightly more but not thick at 

 10.30 a.m. on the 25th. The sample was thick on the morning of the 26th. 



While these trials are not conclusive, they point to the fact that a 

 considerable amount of the preservative would have to be used to keep 

 cream sweet in hot weather, and also indicate that though we may keep 

 a sample sweet by this method, we do not prevent the development of bad 

 flavors which may be more objectionable than simple souring. 



General Conclusions. 



1. Powdered borax, in these experiments, has given as good results 

 as the commercial preservatives, although manufacturers of the latter 

 claim that borax is unsuitable as a preservative, as the following quota- 

 tion from a letter received from one of the firms will show, "We know, 

 from a number of experiments conducted under our personal supervision, 



provided well-made butter of a delicate flavor were in question the 



treated butter must yield a finer flavor than borax-treater butter. 



Borax, as a matter of fact, is a most unsuitable preservative for butter 

 as any practical butter manufacturer must know, as borax is alkaline in 

 its action and would tend to saponify butter." 



We do not find the foregoing results in our experiments, although 

 further work is needed to settle the matter definitely. The borax costs 

 about one-half as much per pound as the commercial preservatives. 



