6. Effect of hop harvest date on the thiol contents in hop cone

Uemoto, M.1, Takoi, K.2, Atsushi, T.2, Itoga, Y.1 and Koie, K.1, (1)Sapporo Breweries Ltd., Hokkaido, JAPAN, (2)Sapporo Breweries Ltd., Yaizu, Shizuoka, JAPAN

Technical Session 2: Hops I
Sunday, June 04, 2017
2:45–4:00 p.m.
Gardens Ballroom

In recent years, many hop varieties with very unique aromas have been bred and grown. Those hops are often called “flavor hops” and give the characteristic fruity flavor to finished beers. Sapporo Breweries Ltd. has investigated the influence of volatile thiols on hop aroma. We mainly focused on two volatile thiols, 4MSP (4-methyl-4-sulfanylpentane-2-on) and 3S4MP (3-sulfanyl-4-methylpentan-1-ol). On one hand, it was reported that 4MSP has a black currant-like odor and 3S4MP has a grapefruit or white wine-like odor. On the other hand, there is little data on a relationship between cultivation technology and quality of hops, which has not sufficiently been investigated. In previous studies, it has been thought that later harvest date results in higher essential oil contents and that the concentration of alpha acids is generally maximized before that of essential oils. However, the impact of hop harvest date on the thiol content in hop cones has not yet been investigated. In this study, we focused on ‘Furano Beauty’ and ‘Furano Magical’ that were bred by Sapporo Breweries Ltd., and ‘Cascade’. These hops were harvested at three harvest times (45 days (normal), 65 days and 75 days) within a 4 week interval. We measured alpha acids and essential oils using American Society of Brewing Chemist standard methods of analysis and the volatile thiols by gas chromatography-tandem mass spectrometry (GC-MS/MS). As a result, with delayed harvest date, the content of 4MSP showed almost no change or slightly decreased, while the content of 3S4MP increased by several times. In addition, we confirmed that the content of 3S4MP in the beer brewed with 65 day hops was several times higher than those in the beers with 45 day hops. In addition, 45 day hop beer and 65 day hop beer were clearly distinguished by sensory tests. From these results, we would propose a method to control the content of 3S4MP in hop cone using only changes in harvest date.

Mitsuhiro Uemoto received a master’s degree from Kyoto University in Japan, where he majored in plant cell biology. He began employment with Sapporo Breweries in 2012 as a hop breeder and researcher in the Bioresources Research & Development Department. He contributed to breeding ‘Furano Honoka’, ‘Furano Rosa’, ‘Furano Flora’, and ‘Furano Blanc’. He is also engaged in research on the genetic marker construction of the bitter acids and essential oils in hop.

View Presentation