EXPERIMENT STATION BULLETINS. 369 



KEEPING QUALITIES OF BUTTER. 



1.— GENERAL STUDIES 

 WILLIAM S. SAYER. OTTO RAHN. AND BELL FARRAND 



Technical Bulletin No. 1. 



INTRODUCTION. 



Up to this time, very little reliable work has been done in this country 

 in the way of demonstrating the nature of the microscopic hfe which is 

 present in butter until it has become unusually rancid, and of showing the 

 successive stages in the decompositions which render it unfit for use. In 

 Europe, where most has been accomplished, the conditions are so radically 

 different as to make much of the work done of scarcely any practical value 

 to us. Little, if any, of the European work has had to do with actual cold 

 storage, and we have found that the conditions obtaining at temperatures 

 below zero centigrade, and those above the freezing point, are so far from 

 parallel, and the changes which may take place so diverse, as not to allow 

 of ready comparison. 



In a work so extensive, it has not been the purpose to settle with any 

 degree of finality any of the many questions with which we have been brought 

 face to face. It is only by concentrated effort persistently directed against 

 single, isolated problems, that such results are ordinarily obtained. There 

 was need, however, for certain definite information, which could be ob- 

 tained only by observing the changes which ordinarily take place in butter 

 under conditions comparable with those of actual practice. Manifestly 

 it is unfair to draw general conclusions from the results obtained from such 

 extremely small samples as have sometimes been used. 



Although the supply of butter is fairly constant and much more nearly 

 meets the demand than is the case with many other foods, still there are 

 times, as in May, June and perhaps July, when there is an excessive supply 

 which may be stored to profit for the scarcity of the late winter, provided 

 that it is of good quality when removed, and therefore salable at that time. 

 It is, of course, not to be expected that a butter which has been kept for 

 some weeks or months will retain all the delicate aroma of a perfectly fresh 

 butter made according to the best known methods. Some butters do, 

 however, come out of storage, after several months,- with a better flavor 

 than other perfectly fresh butters, which have not been so carefully made. 

 Certain butters may even come out of storage better than when placed in. 

 'Again, two lots, when received may score alike, and, though kept under 

 conditions identical, one lot may come out in excellent condition while the 

 other may have deteriorated to such an extent as to render it utterly un- 

 salable. The purpose of this work is simply to give a general view of 

 the changes in cold storage butter and to break up the whole question of 

 the cold storing of butter into single problems which may afterward be 

 worked out separately. 

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