210 PASTEURIZATION 



burnt cream on the coil. If the coil has become so coated it is 

 very difficult to thoroughly cleanse it at best. The secret of 

 easy and proper cleaning- therefore lies in the proper operation 

 of the pasteurizing process. 



After the remnants of cream are removed, the pasteurizer 

 should be rinsed out thoroughly with hot water, freeing it from 

 all traces of alkali. Then it should be thoroughly steamed until 

 "piping" hot, leaving the gate open to allow the condensed 

 steam to pass off. After steaming, the vat cover should be raised 

 so as to insure prompt drying of all parts of the machine. If the 

 vat is so installed as to cause its bottom to slope about If inches 

 to 2 inches for every ten feet, the water will drain out readily 

 and there is no danger of water remaining in the trough of the 

 vat. Immediately before use the next day the pasteurizer 

 should again be flushed and steamed out before the cream 

 enters it. 



Stuffing boxes should not be allowed to leak cream, water, 

 brine, or steam. Glands should be carefully tightened until 

 leaks are stopped. Packing should be renewed as often as 

 is necessary to keep the glands from leaking. Avoid the use of 

 impure calcium brine. Calcium brine containing magnesium 

 chloride causes rapid corrosion of the iron parts of the circulat- 

 ing system, which intensifies the danger of generating elec- 

 trolysis. This is damaging to the machine and injurious to 

 the cream. 



All pumps, cream conduits and strainers should receive 

 daily cleaning and steaming so as to prevent them from be- 

 coming dangerous sources of contamination. 



Advantages and Disadvantages of Continuous and Vat 

 Pasteurization. 



General Practicability. Taking into consideration all con- 

 ditions, such as irregularities of delivery of cream, condition of 

 cream, average intelligence of operator and simplicity of opera- 

 tion, the vat method of pasteurization appears the most practical. 

 This applies especially to conditions as they prevail in the 

 average small creamery. When the daily cream receipts are 

 limited and the shipments or deliveries happen to arrive at ir- 

 regular times of the day, it is difficult to use the continuous pas- 

 teurizer to advantage. When this machine is once started it is 



