BUTTER DIRECTS 483 



7. Use butter cartons only that are incapable of transmit- 

 ting to the butter an oily flavor. 



Metallic Flavor. By metallic flavor is generally under- 

 stood a semblance in flavor to the astringent, puckery and 

 metallic flavor, characteristic of the taste of metallic salts, such 

 as are formed by iron, copper, zinc, etc., in acid solutions. 



This flavor defect is not always sharply defined, often be- 

 ing accompanied by other, more or less pronounced off-flavors. 

 Frequently it borders on oiliness, then again it approaches fishi- 

 ness and occasionally it appears to be a nuance of tallowy 

 flavor. 



Causes of Metallic Flavor. While direct contact with 

 metals and high acid in cream are undeniably essential and 

 fundamental factors in the production of metallic flavor in but- 

 ter, they do by no means always produce this defect. 



This fact suggests that the metallic flavor, similar to the 

 fishy flavor in butter, is the result of a combination of condi- 

 tions, of which all the necessary elements are not as yet def- 

 initely known. 



Slight variations of the factors making up this combination, 

 or slight variations in the extent to which the individual ele- 

 ments of the combination are present, appear to make wide dif- 

 ferences in the exact flavor defect produced. The result may 

 be the characteristic metallic flavor, or it may be an oily flavor, 

 a fishy flavor, or a tallowy flavor, etc. 



Thus experimental results of the writer show that under 

 the majority of conditions, the presence of traces of such metals 

 as iron or copper or their salts, in butter made from sour cream, 

 causes such butter to develop a metallic or a fishy flavor, while 

 the presence of the same metals, or their salts, in butter in 

 which the acid has been completely neutralized, will produce 

 a tallowy flavor. 



Since it is evident that traces of metals or metallic salts 

 are an integral part of the combination of conditions that results 

 in metallic flavor in butter, it is obvious that the condition of 

 the utensils and equipment in which the milk and cream are 

 handled and in which butter is manufactured, exerts a far- 

 reaching influence on the production or prevention of metallic 

 flavor. 



