Sebastian Hinz (1), Andreas Gahr (2), Christina Schoenberger (3), Mark Zunkel (3); (1) Barth Haas Group, Nuremberg, Germany; (2) Hopfenveredelung, St. Johann, Germany; (3) Barth Innovations, Nuremberg, Germany


Breweries occasionally buy and/or use hops from older harvests because of hop shortages and demand fluctuations of beer brands. The hop storage index (HSI) is the main value that breweries use to evaluate the age of hops, although some research studies show this non-specific analysis method does not always correlate well with perceived flavor. In this study, oxidized pellet hops of German Perle and Czech Saaz with three different HSI values of each variety were dosed into 12 different beers to evaluate the hop aroma and bitterness effects in beer. The beers were whirlpool- and dry-hopped. Using triangle tests, no significant difference was found between Perle harvest fresh HSI (0.271) and moderate HSI (0.327) hops, although there was a significant difference between harvest fresh HSI and aged HSI (0.466) hops. Perle beers showed a stronger citrus flavor with harvest fresh hops and strong hoppy, herbal flavors with aged hops. Saaz hops showed similar results in triangle tests with harvest fresh HSI (0.310), moderate HSI (0.397), and aged HSI (0.493) hops. This study found that hops with moderate HSI can be used to replace harvest fresh HSI hops in beer with minimal changes in perceived flavor.

Sebastian Hinz graduated in brewing and beverage technology from Weihenstephan (Fachhochschule) in 2015. In October 2015 he joined the technical team of the Barth-Haas Group as a technical sales trainee. He has been with the Barth Haas Group as an intern during his studies for 2 years. In this time he managed the pilot brewery ABC in Nuremburg and led the internal taste panel. His current projects are focusing on hop aroma transfer during dry-hopping.