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Hammer, Bernard W.

Published onJul 30, 2021
Hammer, Bernard W.

(October 7, 1886-September 6, 1966)

Quick Facts

Dairy bacteriologist, Assistant Professor, Associate Professor, Professor of Dairy Bacteriology, Resident Professor of Dairy Industry Section, Agricultural Experiment Station, Iowa State College, co-developer of the first successful process for manufacturing blue-veined cheese in the United States. 

Portrait of B.W. Hammer, Professor, Dairy Bacteriology, 1912-1943, 1943 by Frank I. Johnson. Oil on canvas. In the Art on Campus collection, University Museums, Iowa State University, Ames, Iowa. U2006.107

Bernard Wernick Hammer was born on October 7, 1886 at Hillsboro, Wisconsin, a son of Robert Hammer and Emma Armbruster Hammer.  He grew up in Hillsboro and graduated from Hillsboro High School in 1904.  Hammer then attended the University of Wisconsin and graduated in 1908 with a BSA degree.  While there, he served as a Private in the Cadets at the University.  After graduation, he was appointed assistant in agricultural bacteriology and worked under Dr. E.G. Hastings for one year.  He then served as a bacteriologist in the Wisconsin State Hygienic Laboratory of the University of Wisconsin (1909—1911).  While working in Wisconsin, he married Edna Quammen in 1909.  They had one son, Robert Quammen Hammer.

In 1911, Hammer was appointed Assistant Professor of Dairy Bacteriology at Iowa State College.  He was promoted to Associate Professor in 1913, to Professor in 1916, and also as Resident Professor of the Dairy Industry Section, Agricultural Experiment Station at Iowa State in 1940.  He was extremely active in teaching, research, and directing research.  In 1921, while teaching at Iowa State, he was awarded a PhD from the University of Chicago.  His dissertation was entitled, The Volatile Acid Production of S. Lacticus and of Organisms Associated With It in Starters.  Among his conclusions was that at least two types of organisms associated with S. Lacticus were important from the standpoint of volatile acidity.  He named the two most prominent ones as Streptococcus Citrovorus and Streptococcus Paracitrovorus.  The dissertation was published by the Agricultural Experiment Station (Research Bulletin No. 63).

Dr. Hammer became a national and international leader in dairy bacteriology.  As early as 1923, he served on the board of the American Society of Bacteriology which issued the first edition of Bergey's Manual of Determinative Bacteriology.  Eight editions of this work were published between 1923 to 1974 and became a widely used international reference work for bacterial taxonomy.  Also, in 1928 Dr. Hammer published Dairy Bacteriology which became a widely used standard textbook in the discipline and appeared in revised editions in 1938, 1948, and 1957.  When the second edition appeared in 1938, the American Journal of Public Health and the Nation's Health recognized Dr. Hammer's work as one of the best sellers in the field of bacteriology.  A reviewer of the second edition commented that “Dr. Hammer's experience in practically all lines of dairy bacteriology and his ability to write clearly on difficult subjects has resulted in a book which is outstanding.” 

Also, working closely as major professor with a graduate student, Clarence B. Lane (who also worked as a Resident Assistant, Dairy and in the Dairy Industrial Section, of the Agricultural Experiment Station for a number of years), the two developed a method of improving the body, texture, and flavor of cheddar cheese.  In 1935, they published Bacteriology of Cheese; Effect of Lactobacillus Casei on the Nitrogenous Decomposition and Flavor Development in Cheddar Cheese made From Pasteurized Milk, which was published as Research Bulletin No. 190 by the Iowa Agriculture and Home Economics Experiment Station.  Dr. Hammer has also been credited as author or co-author of approximately 150 articles in scientific publications.  


He also broke new ground as a co-developer of new inventions which were awarded U.S. Patents.  The work Dr. Hammer performed with Lane on improvements in manufacturing cheddar cheese was eventually patented in 1943 (U.S. Patent No. 2,322,148) under both of their names. They are perhaps best known, however, for developing the first successful process for manufacturing blue-veined cheese in the United States.  It involved using cow's milk instead of the European style using ewe's milk to make Roquefort.  This process is now a standard for the manufacture of blue cheese of which the most famous in Iowa is Maytag Blue Cheese.  Hammer and Lane received U.S. Patent No. 2,132,077 in 1938 for this method of making blue cheese. 

Dr. Hammer also was involved in patent awards with other bacteriologists.  While still at Iowa State, he and his associates were awarded U.S. Patent No. 2,130,643 and 2,130,644 in 1938 for an apparatus for treating lactic fluids in which a steam treatment pasteurizes liquids, removes undesirable odors and flavors, and cools the liquids.  After leaving Iowa State in 1943, Dr. Hammer and the same associates were awarded U.S. Patent No. 2,466,896 for a new dairy process improving the production of high milk fat concentration and from producing butter from that process.  In 1947, he co-patented a milk fat concentrate process (No. 2,423,834), and in 1953, he co-patented a process for further improving butter (No. 2,630,388).

In 1943, when Dr. Hammer retired from his position at Iowa State, he and his wife moved to San Francisco, California, and he became Assistant Director of Research with the Golden State Company, Ltd.  He worked there until 1947 when he resigned that position.  He then moved to Sarasota, Florida and retired there

Dr. Hammer was a member of the American Dairy Science Association, the American Public Health Association, the Society of American Bacteriologists, the International of Milk, Food, and Environmental Sanitarians.   

Dr. Hammer received a number of awards over they years.  In 1937, B.W. Hammer Panegyric by His Former Students at the Iowa State College was published by the Collegiate Press of Ames which contained tributes by many educators, dairy industry leaders, and laudatory comments by Henry Gilman and Martin Mortenson of the Iowa State faculty.  In 1940, he received the Borden Dairy Manufacturing Award for outstanding contributions in the dairy industry.  In 1955, he was awarded the degree of Doctor of Agriculture at Iowa State.  In 1956, he was awarded life membership in the American Dairy Science Association.  He was also listed in several editions of American Men and Women of Science.

After many years of retirement, Dr. Bernard Wernick Hammer died on September 6, 1966 at Sarasota, Florida at the age of 79.

Selected Sources

Most sources on the life and career of Dr. Bernard Wernick Hammer were found online. 

Family information and obituaries were found at 

U.S. Patents were found on Google Patents. 

Other items found online included a history of Bergey's Manual of Determinative Bacteriology; an obituary in the Journal of Dairy Science, January, 1967, Volume 50, Number 1, p. 113; his doctoral dissertation from the University of Chicago; the awards of the American Dairy Science Association; his honorary Doctor of Agriculture degree from Iowa State in 1955; and references in the Val C. Sherman, “Meeting NEW Demands for Cheese, “News for Farmer Cooperatives, Volume 8, Number 7, October, 1941, pp. 14-15; American Journal of Public Health and the Nation's Health, Volume 36, Number 8, August, 1946, p. 841 and in the International Journal of Systematic Bacteriology, Volume 20, Number 1, January, 1970, p. 14.  His major publications with Dr. Clarence B. Lane are No. 183, 190, 237, 291, and 325 in the Iowa State University Digital Repository at  

Hard copy sources include copies of a number of his books including Bacteriology of Cheese: Effect of Lactobacillus Casei on the Nitrogenous Decomposition and Flavor Development in Cheddar Cheese made From Pasteurized Milk are in the General Collection of the Parks Library, Iowa State University.  Copies of the 3rd edition of Dairy Bacteriology and  B. W. Hammer Panegyric by His Former Students at the Iowa State College  are in the Special Collections Department, Parks Library.

In addition, there is an article on Dr. Hammer receiving his PhD in the Iowa State Daily Student, January, 17, 1921, p. 1. 

Information on Dr. Hammer's positions and promotions were found by examining issues of the Iowa State Student and Faculty Directories from 1911 to 1943.



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