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Aroma hop varieties developed for production in the USA—A review
Presenter: Gene Probasco, Hop Breeding Company, John I Haas Inc, Yakima, WA
Co-Authors: S. Kenny, Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA; J. Henning, USDA, Corvallis, OR; and J. Perrault, Hop Breeding Company, Select Botanicals Group, Yakima, WA

During the last 15 years, numerous aroma hop varieties have been developed, tested, and released for production into the hop-growing regions of the USA. Most of these varieties have some parentage derived from the well-known European noble aroma varieties including Saazer, Tettnanger, and Hallertauer Mittlefreuh. The USA-developed aroma varieties generally have analytical data similar to those of the noble aroma varieties. Analytical data that are typical for aroma varieties include alpha-acid and beta-acid contents between 4.0% and 7.0%, respectively, cohumulone contents below 26%, total oils contents below 1.5%, humulene/caryophyllene ratios above 2.4, and storage stability in the medium range typical for hops. Each of these varieties has proven to make excellent beers, and some are being used on a large scale by major breweries while others are being used on a smaller scale by certain micro-breweries. Many of these varieties have been qualified by major breweries as replacements for specific European aroma varieties. All are currently being grown in the USA on acreages ranging in size from 5500 acres for one variety down to less than 50 acres for others; however, the production of any of these varieties can be expanded to meet the needs of any consumer. This paper presents the origin, analytical data, and merits of each of the USA-developed aroma varieties Willamette, Vanguard, Ultra, Sterling, Santiam, Mt. Hood, Liberty, Glacier, Crystal, Cascade, and Palisade.

Gene Probasco received a Master of Science degree in plant pathology from Washington State University. After graduation, he spent six years in hop research at Washington State University before joining John I. Haas, Inc. During his entire time at Haas, he has been in charge of the hop-breeding program and agronomic research. For the past 10 years, he has additionally been responsible for hop production on the company-owned hop farms in the USA and a vice president for John I. Haas, Inc. He is his company's representative member on the Hop Research Council and has in the past served the Council as chairman of the Budget Committee, vice president, and president.