SAI/TING THE BUTTER 341 



and sugar, is frozen, bacteria cease to be able to utilize it and 

 their activity stops. When butter is stored at or above the 

 freezing point of water the liquid portion in both salted and 

 unsalted butter is in solution. In salted butter liquid brine 

 has a retarding influence on some of them, while in unsalted 

 butter ' their development is unhindered. It is obvious there- 

 fore that at ordinary temperatures the unsalted butter will 

 spoil more readily than the salted butter, a fact which is amply 

 borne out in the commercial manufacture and handling of 

 butter. 



But not so when butter is stored at the cold storage tem- 

 perature generally used in this country, i. e. 6 to 10 F. 

 At such low temperatures the moisture in unsalted butter is 

 frozen solid, a fact which makes further bacterial development 

 impossible. In heavily salted butter on the other hand, the 

 freezing point of the brine is very near the storage tempera- 

 ture. The brine therefore remains in solution for a relatively 

 long period of time and the micro-organisms which are capable 

 to resist the concentrated brine are able to continue their work. 

 That the brine in heavily salted butter remains in solution 

 for some time, if it freezes at all after the butter has been placed 

 in cold storage, is clearly shown in the paragraph relating to 

 "The Effect of Salt on the Moisture Content of Butter.' 1 

 Unsalted and lightly salted butter lost practically no moisture 

 in cold storage, while heavily salted butter lost from one to 

 three and one-half per cent moisture. Similar results are re- 

 ported by Washburn. 1 These findings are in no way contradic- 

 tory to those obtained by the investigators previously quoted 

 who reported that salted butter kept better than unsalted but- 

 ter, because of the differences in the temperature at which 

 their butter was stored. 



The earlier impression among buttermakers and also 

 quoted in some of the text books was that salt covers up the 

 bad flavors in butter, and it used to be recommended that but- 

 ter of inferior quality should be salted heavily in order to hide 

 the undesirable flavors. Our latest findings on this point do 

 not bear out this assumption. On the contrary, experience has 



1 Washburn. Influence of Salt on Storage Butter, Journal of Dairy Science, 

 Vol 1, No. 2, 1917. 



