The Gerber method is a primary and historic chemical test to determine the fat content of substances, most commonly milk and cream.
[2] 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.
[4] Milk fat is separated from proteins by adding sulfuric acid.
The fat content is read directly via a special calibrated butyrometer.
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).