ON BUTTERMAKING 41 



How much salt can be incorporated in butter? 



As much as 7 per cent or 8 per cent, but then 

 most of it is in an undissolved state. It is difficult 

 to incorporate more than 3 per cent of dissolved 

 salt. 



How is butter tested for its salt content? 



1. Weigh into a glass beaker 10 grams of butter. 

 Add about 20 c. c. water and warm the mixture to 

 melt the butter. Then transfer the butter and 

 water to a separatory funnel. Insert the stopper 

 and shake for a few minutes. Then allow the mix- 

 ture to stand a few minutes until any remaining 

 fat has collected on the surface. Then draw the 

 water into a flask, being sure that no fat passes 

 through. Again, add hot water to the beaker and 

 repeat the washing in the funnels several times, 

 using 15 c. c. water each time. 



Determine the sodium chlorid or salt in a meas- 

 ured part (10 c. c.) of the liquid by titrating with 

 standard silver nitrate solution, using potassium 

 chromate as an indicator. 



One c. c. -^ silver nitrate solution equals .005837 

 grams of salt. 



To determine the total amount of salt divide the 

 total number c. c. of water used by 10 and multiply 

 by .005837. This will give the total number grams 

 of salt in 10 grams of butter. 



Then, knowing the amount present in 10 grams, 

 it is an easy matter to determine the amount in 100 

 grams by multiplying by 10. This gives the per- 

 centage of salt in the butter tested. 



2. Gray's salt test. A representative lo-gram 

 sample of butter is placed in a small glass dish. 



