The brewing value of Amarillo hops (Humulus lupulus L.) grown in northwestern USA: A preliminary study of terroir significance

The brewing value of the hop variety Amarillo as a dual-purpose hop delivering both bitterness and flavour to beer is undisputed. Our brewing studies of wide-ranging hop varieties revealed that the qualities of Amarillo hops grown at different locations in northwestern USA (Idaho and Washington) led to divergent flavour observations in Amarillo-derived single hop beers. Profiling of hop oil volatiles in both the hops and the beers delivered convincing proof of the significant impact of the specific growth location (terroir). Multidimensional scaling analysis clearly distinguished the Amarillo hops from the two regions. The Amarillo hops of the Idaho terroir, in comparison to these of the Washington terroir, were characterized by lower citrusy and floral notes in combination with increased contributions from fruity, spicy and resinous odour descriptions. This preliminary study indicates that brewersmust rely on desired hop varieties from the same terroir in order to achieve consistent hoppy aromas in their beers.