454 MILK AND MILK PRODUCTS; DAIRY FARMS 



Cool and dissolve the ash in 20 cc. of pure, clean water. Transfer 

 the 20 cc. of the ash solution to a glass beaker or a white cup. Add 

 five or six drops of a water solution of potassium chromate. This will 



turn the solution a lemon-yellow color. Run in from a burette an 



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normal solution of silver nitrate. Thoroughly mix the solution as 

 the silver nitrate is added. When the color of the solution turns to 

 an orange-yellow, enough silver nitrate has been added to neutralize 

 all the salt. Then multiply the number of cc. of silver nitrate used by 

 .00585. Divide this result by 5, the number of grams of cheese 

 taken, and multiply the quotient by 100. This is the per cent of salt 

 in the cheese. 



Care should be taken not to run in too much silver nitrate. If too 

 much silver nitrate is used, the color will be a dull brick-red, and in- 

 correct results will be obtained. An normal solution of silver 



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nitrate, which is accurate enough for the purpose, may be made by 

 dissolving 17 grams of silver nitrate in 200 cc. of water and then 

 making the solution up to 1000 cc. or one liter. 



Over-run in butter-making (Pa. Sta. and U. S. Dept. Agric.). 



Over-run in butter is the amount of water, casein, and salt incor- 

 porated in the butter-fat in making butter. Creamery over-run, how- 

 ever, should always be computed from the number of pounds of butter- 

 fat received and the pounds of butter sold. 



The formula for calculating over-run in percentage is as follows : 



Pounds of butter made pounds of butter-fat received .. ., nrk 



A iuu 



pounds of butter-fat received 



= per cent over-run. 



In a whole-milk creamery it is possible to obtain from 18 to 20 

 per cent over-run and have only 14 to 14 1 per cent moisture in the 

 butter, while in a creamery where hand separator cream is received, 

 20 to 22 per cent over-run can be obtained. This is shown by the 

 following two examples : 



