88 HINTS ON DAIRYING. 



of the rennet is rather slow, it is better to wait a tew 

 minutes for the curd to harden a little, while with 

 your hand you carefully rub down the side of the vat, 

 thus removing all the curd that may be adhering to it. 

 Not over five minutes waiting, as a usual thing, is neces- 

 sary, and generally there need be no waiting. But as 

 soon as the heat is started, begin to gently stir the curd 

 with a rake, by passing it down into the middle of the 

 vat and gently raising the curd on each side. If uncut 

 pieces appear, carefully separate thorn with the teeth 

 of the rake. Keep up this stirring, which may be more 

 violent after the curd hardens, until the whole is heated 

 up to 98 or 100 degrees or to blood heat. The reason 

 for constant agitation is to keep an even temperature 

 throughout the mass and prevent the curd from packing. 

 This secures even action of the rennet. The reason for 

 going to blood heat is because rennet is most active at 

 this point. It is the temperature indicated by Xature. 

 It is the one at which we digest our food, and the one at 

 which the calf's stomach forms curd and afterwards di- 

 gests it. The pepsin or gastric juice is more potent at 

 blood heat, and this pepsin or rennet is what does the 

 work. The heat does not cook the curd in the vat any 

 more than it cooks the milk in the cow's udder. We 

 choose 98 degrees as the proper temperature because the 

 digestive or cheesing process of the rennet goes on faster 

 at this point. To go above or below it is to lose instead 

 of gain. This temperature sluuld therefore be main- 

 t'linecl until the curd is ''coikeJ" that is, until the ac- 

 tion of the rennet has expelled the proper amount of 



