Gerber method
The Gerber method is a primary and historic chemical test to determine the fat content of substances, most commonly milk and cream. The Gerber method is the primary testing method in Europe and much of the world. The fairly similar Babcock test is used primarily in the United States, although the Gerber method also enjoys significant use in the U.S. as well. The Gerber method was developed and patented by Dr. Niklaus Gerber of Switzerland in 1891. Milk fat is separated from proteins by adding sulfuric acid. The separation is facilitated by using amyl alcohol and centrifugation. The  fat content is read directly via a special calibrated butyrometer. Gerber developed specialized butyrometers (tubes), pipettes, and centrifuges. Water baths built specifically for the Gerber tubes are often used. The test is still in widespread use today and is the basis for numerous national and international standards such as ISO 2446, International Dairy Federation (FIL) Regulation 105, BS 696 (United Kingdom), and IS 1223 (India). Larger facilities may prefer to use faster analysis techniques such as infrared spectroscopy as these greatly reduce the potential for user error and reduce the time and COSHH requirements. The test continues to be improved  and standardized. Problems likely to be encountered during Gerber butterfat content determination. The two major defects associated with the Gerber method include: