DAIRYING 57 



the common practice being to make trips every other day in sum- 

 mer and twice a week in winter. When cream is kept for so long a 

 time as this it is often sour before it leaves the farm. This, in many 

 cases, is caused by carelessness or because no great effort has been 

 made to keep the cream cool until it is delivered to the haulers. A 

 certain amount of such tainted cream is usually gathered on each 

 route, and when no precautions are taken by the gatherers to keep 

 the inferior cream separated from the sweet cream, that has been 

 well cared for, the bad qualities of the former are transmitted to 

 the entire lot and the butter suffers a loss in quality on this ac- 

 count. Such inferior cream is not always found on every route ; but 

 even when the many patrons deliver a perfectly sweet cream to 

 the gatherers, there will be a great variety in the flavors and in the 

 freshness of the different lots; and this lack of uniformity in the 

 cream will necessarily have its influence on the quality of the 

 butter. Some of the defects of gathered cream butter are often be- 

 yond the control of the butter-maker, and he is obliged to do the 

 best he can with that which is brought to him. 



499. In hot summer weather an acidity of 0.6 per cent, is 

 often developed in the cream w r hen it is delivered to the factory; 

 such cream is sour enough to churn, but since it is usually very 

 warm, it could not be churned at once without suffering a large 

 loss in the butter milk; the sourest lots would churn first and 

 leave some of the less ripened cream in the butter milk. This loss 

 may be avoided by stopping the ripening immediately, either by 

 cooling or by heating the cream to a temperature that will check 

 the growth of the bacteria which are responsible for the cream 

 souring. 



500. The course sometimes adopted in handling this cream 

 is to place large pieces of ice in the cream as soon as it arrives 

 at the factory; usually about 6 p. m. The vats of cream are left 

 to cool as best they may during the night, with an occasional stir- 

 ring of the floating pieces of ice through the evening. The next 

 morning it will be noticed that the acidity of the cream has not 

 increased much; but the ripening has continued, and the tem- 

 perature of the cream may be near 60 deg. F. At this temperature 

 the cream is churned, and the butter obtained is of a more or less 



