Effect of “Late Harvest” of Hops (<i>Humulus lupulus</i> L.) on the Contents of Volatile Thiols in Furano Beauty, Furano Magical, and Cascade Varieties
Mitsuhiro Uemoto, Kiyoshi Takoi, Atsushi Tanigawa, Koji Takazumi, Kensuke Ogushi, Koichiro Koie, Narushi Suda
Abstract
In recent years, many hop varieties with unique aromas, so-called "flavor hops", have been bred and grown. Here, we investigated the effect of late-harvested hops using three flavor hop varieties; Furano Beauty, Furano Magical, and Cascade. The sample hops were harvested at different days after flowering (DAF): DAF 45 (normal harvest), DAF 65, DAF 75, and DAF 85. We measured the volatile thiols in sample cones. The results indicated that 4-methyl-4-sulfanylpentane-2-one contents showed almost no change or a slightly decrease with a delay in harvest, whereas 3-sulfanyl-4-methylpentan-1-ol (3S4MP) content in late-harvested samples increased several fold in comparison with normal-harvested samples. Additionally, 3S4MP contents in the beers brewed with DAF 65 samples were several times higher than those using DAF 45 ones. From these results, we propose a new method to control 3S4MP content in hop cones by changing its harvest date.