Requirements (Instruments, Chemicals & Other)
Sample of milk
Sulfuric acid (90%)
Amyl alcohol
Centriguge
Waterbath
Pipette
Butyrometer
Lactometer
Thermometer

Procedure

1. Pipette out 10 ml H2SO4 and transfer to the butyrometer.
   
2. Pipette out 10.75 ml milk and add to the butyrometer.
   
3. Pipette out 1 ml amyl alcohol and add to the butyrometer and close the butyrometer firmly with stopper.
   
4. Shake the butyrometer to mix the contents thoroughly.
   
5. Place the butyrometer in the water bath at 65°C for 5min.
   
6. Take out the butyrometer from water bath and transfer it to the centrifuge
   
7. Place another butyrometers filled with water (21.75 ml) into the centrifuge to balance the rotating disc.
   
8. Centrifuge the mixture at 1100 rpm for 4 minutes.
   
9. Remove the butyrometer from the centrifuge and place in the water-bath at 65°C for 3 min.
   
10. Record the level of the fat layer on the butyrometer scale.
    
11. Take 50 ml of milk in a measuring cylinder, insert the lactometer and record the lactometer reading (LR)
    
12. Dip the thermometer, measure the temperature of the milk and calculate the corrected lactometer reading (CLR)
    
13. Calculate the SNF percent using the formula:
    SNF (%)=CLR/4+0.25F+0.6