Description
- The Gerber Method is a primary and historic chemical test to determine the fat content of milk and other substances. The Gerber Method is the primary testing method in Europe and much of the world.
- 1. Carryout through mixing of milk before testing. 2. Amyl alcohol must be pure. 3. Sulphuric acid is to be added gently by the sides of the butyrometer without wetting the neck of the butyrometer. Avoid direct pouring of milk on acid.
- 4. The three fluids viz. Sulphuric acid, milk and amyl alcohol should be added gently, so that they form three distinct layers. 5. Rubber stopper should be dry, clean and without crack. 6. Before centrifuging the butyrometer, see that there is no curdy white material left undissolved. 7. The centrifuge must be properly balanced.
- 8. Always carry out the test in duplicate. 9. Butyrometer should be free from Na2Co3 (soda ash) if cleaned by Na2Co3 otherwise it lowers the specific gravity and strength of Sulphuric acid. 10. Use butyrometer stand for shaking of butyrometer contents to dissolve the SNF content of milk.
Gerber Instruments founded by Dr. Niklaus Gerber is a pioneer for the quality determination of fat in milk and dairy products and solubility of milk powder according to Gerber for more than 120 years. The Gerber method is being used as reference method to determine the fat content in milk worldwide. 1. Put the clean and dry butyrometer in a butyrometer stand with open mouth upwards. 2. Run 10 ml of sulphuric acid with the tilt measure in the butyrometer. 3. Pipette out 10.75 ml of milk sample gently by the side of butyrometer, whose temperature is about 15-21 degrees C. 4. Pour 1 ml. of amyl alcohol with tilt measure. 5. Stopper the butyrometer with the help of lock stopper using regulating pin/guiding pin. 6. The tube is well (mixed) shaken till mahogany red colour is obtained. Keep the butyrometer in hot water bath till it attains 15-21 degrees C and the butyrometer are placed in the centrifuge at 1100 rpm for 4 minutes. 7. Take out the butyrometer in an upright position with the stopper end down wards. 8. Keep the butyrometer in hot water bath at (65 degrees C) for some time. 9. Note the reading. Reading should be taken from bottom of the fat column to lower border of meniscus on the scale.