Hops are natural ingredients used to impart bitterness and flavor to beer. Recently, new varieties of hops have attracted global research attention. The Sorachi Ace variety, in particular, interests many craft brewers. This hop imparts characteristic varietal aromas, including woody, pine-like, citrus, dill-like, and lemongrass-like, to finished beers. Here, we investigated specific flavor compounds derived from Sorachi Ace using selectable one-dimensional or two-dimensional gas chromatography−olfactometry/mass spectrometry and head space-solid phase microextraction−gas chromatography−mass spectrometry. The results showed that a unique volatile compound, geranic acid, was present at a significant level only in the test beer brewed with the Sorachi Ace hop. Furthermore, sensory evaluation techniques revealed that geranic acid has very unique characteristics. This compound is not odor-active but functions as an enhancer for hop-derived terpenoids at subthreshold levels.

The lipoxygenase‐1‐less (LOX‐less) trait has positive effects on beer quality, in particular, improvement of flavour stability related to the reduction of beer‐deteriorating substances such as trans‐2‐nonenal. ‘Ryohfu’ is the only spring‐sown malting barley variety grown in Hokkaido, located in the northern part of Japan, and has been used in the Japanese brewing industry for over 20 years. ‘Satuiku 2 go’ was developed as the first LOX‐less malting barley variety in Japan by successive back‐crossing with molecular marker‐assisted selection to introduce the LOX‐less trait into the recurrent parent ‘Ryohfu’. The agronomic performance and general malt quality of ‘Satuiku 2 go’ were almost equivalent to those of ‘Ryohfu’. Wort and beer analyses at the pilot‐scale brewing trial indicated that the LOX‐less trait had little effect on the general characteristics. In contrast, the beers made from ‘Satuiku 2 go’ malt exhibited reduced levels of trans‐2‐nonenal and trihydroxyoctadecenoic acid. The sensory evaluation demonstrated the superiority of ‘Satuiku 2 go’ beers stored under differing conditions in terms of staleness. It can be concluded that the LOX‐less trait was effective in different genetic backgrounds of the recurrent parents used for the development of LOX‐less malting barley varieties. Copyright © 2018 The Institute of Brewing & Distilling

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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.