458 BUTTER STORAGE 



These facts emphasize the probability that there are many 

 factors which are instrumental in the production of a specific 

 flavor defect through their joint action, while each separate fac- 

 tor, though necessary for the combination that produces the 

 defect, is by itself alone incapable of so doing. As a concrete 

 example of this may be quoted the case of tallowy butter the 

 specific causes of which have been determined with certainty. 1 

 Oxygen carriers and catalizing agents, such as certain metals 

 and their salts, especially copper and copper salts, are capable of 

 making butter tallowy. These agents are present in average 

 butter to a very small extent and in butter containing a normal 

 per cent acid and kept in cold storage they fail to produce 

 the tallowy flavor. If this butter is made from over-neutralized 

 cream, or is wrapped in parchment which was not entirely freed 

 from the ammonia used for the neutralizing of the sulphuric 

 acid used in the parchmenting process, the butter so wrapped 

 may become tallowy very rapidly, especially when it is exposed 

 to room temperature. In this case the alkali, which alone does 

 not make butter tallowy, is a necessary part of the combination, 

 in which copper may be the fundamental cause of the tallowy 

 flavor. 



The texture of the butter usually shows marked changes 

 only after prolonged cold storage. The grain of the butter 

 gradually breaks down giving such butter a more or less 

 crumbly and pasty consistency. 



Summary of the Effect of Cold Storage on the Quality of Butter. 



Summing up the most important phases of our present 

 knowledge of the effect of storage of butter on its quality the 

 following points are emphasized : 



1. Age tends to deteriorate the flavor of butter. The 

 rapidity and intensity of this deterioration, other factors being 

 the same, is influenced largely by the temperature of storage. 

 At the usual temperature of commercial cold storage, 6 to 10 

 F. the changes in flavor are usually very gradual. 



2. The most predominating flavor defect which butter de- 

 velops in cold storage is the flavor known as cold storage flavor. 

 In the case of butter that was of good quality when it went 



x Hunziker and Hosman, Tallowy Butter, Its Causes and Prevention, 

 Journal of Dairy Science, Vol. I., No. 4, 1917. 



