We began hop research in 2010 at the SROC. Hops are a perennial vine, and the female inflorescence is used to add bitterness, and sometimes flavor and aroma, to beer. Craft breweries in the Midwest are interested in using local materials, and farmers are interested in (profitable) diversification and perennial cropping systems. Currently, nearly all hops commercially grown in the US are from farms averaging >400 Acres in Washington, Oregon, and Idaho.
We have begun to work toward answering the following questions:
What varieties grow well here?
Hops have not been grown commercially in the upper midwest since the hop craze in Wisconsin in the 1860's and '70's. Since then, a tremendous amount of new germplasm has been developed in Germany, England, and the US. Properties of European 'Noble' varieties have been bred into newer, high-yielding varieties (Mt. Hood, for example). Varieties with 'English' character, but enhanced disease resistance and much higher yield have been developed (Challenger, Willamette). And since the 1970's, US breeding programs have developed numerous varieties with distinct flavor and aroma properties (Cascade, Chinook). Hops with much higher %Alpha Acid content have been developed since the 1870's as well (Perle, Northern Brewer, Centennial, for example). However, none of these varieties were bred with a Midwest US climate or production system in mind. Much newer varieties, like Simcoe, Amarillo, and Citra have been developed, but these varieties are proprietary and not widely available to Midwestern growers. So our first goal is to search for varieties that will be vigorous and tolerate diseases and pests in the climate and soils of the upper Midwest.
What varieties will grow on a low trellis here?
Large growers in the Pacific Northwest have developed specialized equipment to deal with growing and harvesting hops on +18-foot trellises. Growers in the midwest are starting out smaller (<10 Acres, often much smaller). Growing hops on a 10-foot trellis and permanent polypropylene mesh (instead of annual stringing of twine for each plant) would simplify trellis installation and maintenance, scouting and pest/disease control, and some labor-intensive spring activities. However, harvest will have to be by hand, in the field, unless another means of support is used or until inexpensive machinery is available. Many growers are currently trying to install a trellis as high as they can reasonably get with the equipment they have. Without access to the few proprietary dwarf hop varieties that do exist, we are exploring what widely-available commercial varieties will perform acceptably on a low trellis in the upper Midwest.
What is different about the plants when they are grown on a low trellis compared to on a high trellis?
The effects of trellis height on cone size and pickability, arm length, node and height of lowest flower, alpha and beta acid content, and yield will be compared in 3 varieties (Mt. Hood, Nugget, and Willamette) on a 16-foot and 10-foot trellis. We will make the comparisons so growers can understand the effects of reducing final plant height on cone quality, growth properties, and yield.
What is the xanthohumol and bitter acid content of the varieties we are growing?
Xanthohumol and bitter acids have properties of interest relating to human health. Finding a variety with a high xanthohumol:bitter acid ratio would increase the dose of xanthohumol for a given beer relative to a beer bittered with a low-ratio hop. We are interested in the healthful compounds present in hops as part of our nutraceutical research.
The work we are starting will help us to determine what varieties and growing systems to study in the future.
Hop pedigrees are interconnected and complicated but can be helpful for understanding existing varieties or for creating new varieties. This 24×36-inch poster displays the pedigrees for over 40 varieties of hops developed by English, American, German, and Japanese breeding programs. From Brewer's Gold to Bravo, Centennial to Millenium, Chinook to Challenger, the connections among hops found in many commercial beers are compiled in a visually appealing way, perfect for hanging in your brewery or lab.