500 BUTTER 



ing of butter accomplish this to a large extent, provided that 

 recontamination of cream and butter is avoided by sanitary con- 

 ditions of vats, churns and packing equipment and proper treat- 

 ment of tubs, cubes, liners and wrappers. 



3. Protection of the butter against air, light and heat, and 

 the absence in it of catalizers, such as metallic salts, high acid, or 

 alkali, will minimize the action of rancidity-producing agencies 

 which may be present in butter. Churn the cream at a low 

 acidity, do not overneutralize and put the butter in the sealed 

 package, and refrigerate it, as promptly as possible after manu- 

 facture. 



Woody Flavor. This is not a very common flavor defect 

 of butter, though "epidemics" of woody-flavored butter have 

 occurred, causing serious objection on the market. 



The most common cause of butter with a woody flavor is 

 probably the churn. New churns that have not been properly" 

 treated before use, may impart to butter a woody flavor. Churns 

 also that are in unclean condition, or the wood of which has 

 become decayed, may become infested with certain species of 

 microorganisms, especially molds, that are capable of giving the 

 butter a woody taste. Such conditions are especially liable to 

 happen with churns that are not in daily use, giving the micro- 

 organisms an opportunity to work into the cracks between the 

 staves and also into the pores of the wood, where they are diffi- 

 cult to be reached, dislodged or destroyed, and where they form 

 a continuous source of contamination of succeeding batches of 

 cream and butter. A case of this type, resulting in woody-flav- 

 ored butter, was noted and investigated at Purdue University 1 . 

 The churn that produced the woody flavor was used only once 

 per week. Investigation showed that the woody flavor was due 

 to a mold lodged in the cracks of an apparently clean churn. 

 This mold produced the same intense woody flavor when inocu- 

 lated and propagated in sterile milk. For treatment and disin- 

 fection of churns see "Preparation of Churn," Chapter X. 



Salt, packed in barrels of decayed and infected wood, is also 

 known to be capable of transmitting to butter a woody flavor. 



1 Hunziker and Switzer. Results not published, 1916. 



