WORKING THE BUTTER 363 



receives in the commercial combined churn and worker incor- 

 porates air and the probability of actual air expulsion in this 

 case is by no means remote. 



However, it is unquestionably a fact, that any air perma- 

 nently present in the butter, becomes very finely divided and 

 emulsified by overworking and in this form a much larger area 

 of the butter becomes exposed to this air, so that, even without 

 the actual incorporation of additional air, the injurious effect 

 of the air present is greatly magnified. 



The fact that overworking gives the butter a whiter color 

 is not necessarily due to the incorporation of additional air as 

 Rogers concluded, but it is invariably caused by the reduction 

 of the size of the water droplets as shown by Hunziker and 

 Hosman. Unsalted butter is always whitef than salted butter, 

 both, before working and during any part of the working proc- 

 ess. Microscopic examinations of butter during all stages of 

 the working process, by Hunziker and Hosman, conclusively 

 show, that in unsalted butter the water droplets are exceedingly 

 minute while in salted butter they are relatively large, espe- 

 cially during the early stages of the working process. And, 

 again, the whitening effect due to working takes place even when 

 the butter is submerged in water during the working process, 

 eliminating any possibility of incorporation of additional air. 



It is also not improbable, though not experimentally proven, 

 that the destruction of the grain of the butter, as is the case in 

 overworking, tends to lessen the resistance of the fat to such 

 oxidizing agencies as air, metallic salts, etc. and therefore hastens 

 its deterioration. 



When the butter has been worked enough, the workers are 

 stopped and the churn is given another revolution or two in 

 order to deposit the butter on top of the workers from where 

 it can be easily removed and transferred to the tubs or cubes, 

 or other receptacles. 



Before removing the butter from the churn it should be 

 accurately tested for moisture content, so that if the moisture is 

 excessive, or deficient, it may be corrected by further working. 

 For directions on controlling moisture see also chapter on Com- 

 position of Butter Moisture Control Chapter XVIII. , and for 

 directions on moisture tests see Chapter XXII. 



