Hunziker wrote dairy articles and textbooks used throughout the world, developed dairy curricula, advocated for dairy laws, and developed standard testing methodology. Hunziker authored The Butter Industry, Prepared for Factory, School and Laboratory, a well-known text in the industry that enjoyed at least three editions (1920, 1927, 1940). The Butter Industry (or its author) was "recognized by the Ontario Department of Agriculture as an expert on butter quality".The Queensland Department of Agriculture and Stock officially recommended The Butter Industry with only 4 other texts for those studying to test dairy products. A book that Hunziker originally self-published in 1914, "Condensed Milk and Milk Powder: Prepared for the Use of Milk Condenseries, Dairy Students and Pure Food Departments", was republished in a seventh edition in October 2007 by Cartwright Press. According to one book review: "The popularity of this book may be judged by the fact that this is the fourth edition, the three previous editions having long since been exhausted. The book is the most important contribution on the condensed milk and milk powder industry. It should be in the library of the teacher, the student or factory man interested in any phase of the condensed milk and milk powder industry." Both books are listed by Cornell University as "Core Historical Literature of Agriculture". In the 1920s, Hunziker initiated a "dairy school over the air"—a radio program on WGN for which dairy experts were invited to discuss various issues. Hunziker was a director of the National Dairy Council and is listed in The Ten Master Minds of Dairying. Individual article, compiled into "The Ten Master Minds of Dairying". Republished Detroit, Michigan: Gale Research Company, 1967, ; New York, Burt Franklin, 1970, When the World's Dairy Congress was held in the U.S. in 1923, the U.S. Department of Agriculture selected Hunziker to head the industry and economics program. He later represented the United States at World Dairy Congresses in London, 1928; Copenhagen, 1931; Berlin, 1937; Stockholm, 1949; and The Hague, 1953. He obtained several United States patents, including: and . At Blue Valley, Hunziker established a research program for 22 creameries and two milk plants. In 1932, Purdue University bestowed an honorary doctoral degree in science. He retired from Blue Valley Creamery in 1939 to work as a consultant. In 1942, O F Hunziker was honored with the first ADSA honorary life membership. Hunziker was awarded numerous international honors for his work, including:
