His recent published study on hop terroir backs up what brewers have known anecdotally—that where a hop is grown can have significant impact in flavor and aroma. But just how much impact is possible, and what causes it?
Tom Shellhammer’s research has been crucial for helping brewers, as well as barley and hop growers, gain deeper understanding of brewing ingredients and how they actually work. As a food science professor at Oregon State University, he’s led critical studies, including a well-known study on hop creep. His latest project is a wide-ranging, multiyear study to understand the impact of terroir on hops, and the results of the first year of the study have just become available. In this episode, Shellhammer discusses the study—what they studied, how they studied it, what the results show, and what we have yet to understand.
Along the way, Shellhammer discusses:
- what hop terroir is (weather, soil, latitude), and what it isn’t (geomorphology)
- the impact of farming management practices
- the goals and parameters of the project
- measuring compounds, but also expression through sensory, to understand terroir impact
- how hop growers measure maturity on the bine
- the logic behind the focus on Cascade and Mosaic varieties
- the compounds at play, including monoterpene alcohols and thiols
- clustering of groups of flavor and aroma compounds based on location
- how the chemical compound analysis translates into finished beer
- magnitude of the differences in terroir and the potential for impact
- impact of microbiome in soil
- the scale of difference in the qualitative and measured factors in the study
And more.