Babcock's Revolutionary Dairy Invention | Wisconsin Historical Society

Historical Essay

Babcock's Revolutionary Dairy Invention

Wisconsin Historical Museum Object – Feature Story

Babcock's Revolutionary Dairy Invention | Wisconsin Historical Society
EnlargeBabcock centrifuge for ice cream, 1948

Babcock centrifuge for ice cream, 1948

This relatively simple centrifuge (top) is the key instrument required to conduct the Babcock test. Dairyman Louis Patrick also needed an assortment of pipettes, glass measures, and Babcock test bottles to test milk and a scale (above), modified to hold Babcock test bottles, to test cream. Wisconsin Historical Museum object #1948.589


Babcock with tester, 1926

Dr. Stephen Babcock with an electric version of his centrifuge butterfat tester in a University of Wisconsin-Madison laboratory, c. 1926, years after his official retirement. Source: WHI-5585

Babcock butterfat tester set used
in Adams County, Wisconsin, c. 1895.

(Museum Object #1948.589; donated to the Society by Elsie Schieber Patrick)

Wisconsin will always be known as America's Dairyland, but there is more to the moniker than just catchy slogan appeal. Besides being a prolific dairy producer, Wisconsin was also a major contributor to the development of the modern dairy industry. Louie Patrick used this Babcock tester, invented in Wisconsin, to measure the butterfat content of milk and cream on his dairy farm near Grand Marsh (Adams County), Wisconsin, c. 1895-1900. Even though the equipment and the test itself were relatively simple, the science that created them sparked a revolution in dairy production.

To encourage farmers to improve the quality, not just the quantity, of their milk for butter and cheese making, creameries and cheese factories needed a simple, fast way to determine the quality of milk and thus pay farmers a higher price for better milk. University of Wisconsin Professor Stephen M. Babcock provided the solution in 1890 by perfecting the test that bears his name. The test did not require significant time or expensive equipment and could be conducted on the farm and in the factory.

In the test, milk is poured into a special Babcock test bottle with a graduated neck. Sulfuric acid is added to the sample, which quickly dissolves everything except the fat. This butterfat floats to the top because it is lighter than the acid and what is left of the milk sample. The test bottle is then placed into the Babcock tester and spun for several minutes to further separate the contents. The centrifugal force gathers the butterfat into the neck and an accurate butterfat percentage of the sample is obtained by reading the graduated markings.

Born in New York in 1843, Babcock graduated from Tufts University in 1866. He studied at Rensselaer Polytechnic Institute and at Cornell before receiving his doctorate in organic chemistry from the University of Gottingen, Germany, in 1879. Babcock first began experimenting with milk analysis while at the New York Agricultural Experiment Station in 1882. In 1887 he took a position in agricultural chemistry at the University of Wisconsin. Babcock also became chief chemist at the Wisconsin Agricultural Experiment Station and was its assistant director from 1901 until his retirement in 1913.

Upon Babcock's arrival in Wisconsin, the state's dairy farmers were transitioning from wheat to dairy production. At that time every farmer received the same price for a quantity of milk, regardless of its fat content. There was no incentive to produce superior or even a consistent quality of milk and some farmers would dilute their milk with water. This predicament plagued the dairy industry and led Babcock to begin testing the butterfat content of milk.

Throughout the 1880s, scientists around the world were developing butterfat tests but they were often inaccurate and inconsistent. Babcock's improvement of the centrifugal test proved to be the first practical and reliable appraisal of milk quality. This made it possible to fix standards for milk inspection and to set fair milk prices according to quality. The test made it relatively easy to determine which farmers watered or skimmed their milk.

The Babcock test placed dairy manufacturing on a businesslike footing and provided a huge impetus for dairy herd improvement. Dairymen, like Louie Patrick, performed the test on the farm and began to selectively breed the cows that produced the best milk, thus improving herd quality. Within a generation Wisconsin led the nation in milk and cheese production. Babcock's test and testing device, which he never patented, won grand prizes at the Paris (1900) and St. Louis (1904) international expositions. It was likened in importance to the innovations of the steam engine and the cotton gin, and all over the world Babcock's name became a household word.

[Sources: Lampard, Eric E. "The Rise of the Dairy Industry in Wisconsin: A Study in Agricultural, Change, 1820-1920" (Madison, WI: The State Historical Society of Wisconsin Press, 1963); Frandsen, Prof. J.H. (ed.). "Dairy Handbook and Dictionary" (Amherst, MA: J.H. Frandsen, 1958); Matt, Morris C. "Kimble Manual for Sampling and Testing Milk and Milk Products" (Toledo, OH: Kimble Glass, Division of Owens-Illinois Glass Co., 1951?).]


Posted on May 31, 2007