272 DAIRY TECHNOLOGY 



other system; but the general process is similar in all 

 cases, the differences being in the details only. 



These factories manufacture about 60,000,000 pounds 

 of renovated butter per annum. 



Only the best grades of packing stock are used in this 

 product; the manufacturers have learned that it is im- 

 possible to make a marketable article from old rancid 

 stock. Such material is of value only when used for soap- 

 grease. 



The tendency to-day is toward selling cream from the 

 farm; while some years ago it was largely made into butter 

 which finally went to the renovating factories. The former 

 method is more profitable and handier to the farmer, and 

 is more in accordance with general economical principles. 



The Processes of Manufacture. 



Melting. The butter is brought into the factory in 

 barrels and dumped into the melting tank. These melt- 

 ing tanks are of many different designs, one form of which 

 is a tank having a coil near the bottom through which 

 passes hot water. The vat is also jacketed and surrounded 

 with hot water. The butter is emptied from the barrels 

 into the vat, where it remains until completely melted; 

 then the butter-fat oil is run out at one end through a 

 strainer to remove the paper, wood and other foreign 

 matter occasionally found in the raw material. As this oil 

 runs from the vat and through the strainer it is pumped 

 into steam-jacketed, cylindrical iron tanks, where it is 

 held at a temperature of about i2oF. for two to three 

 hours to permit the curd to settle out. This " slush," as 

 the settlings are called, is drawn out through a valve at 

 the bottom of the tank, and run through an old-style, 



