406: Dr. Tom Shellhammer and Dr. Ron Beatson Discuss the Impacts of Genetics, Terroir, and Pick Timing on New Zealand Hops
Mar 28, 2025
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Dr. Ron Beatson, a retired hop breeder known for his work at Plant & Food Research, joins Dr. Tom Shellhammer from Oregon State University, who studies hop oils and terroir. They explore how genetics and terroir influence hop flavors, uncovering the origins of aromas like onion and garlic. The dynamics of harvesting Nelson Sauvin and the use of cover crops for soil health are discussed, alongside unique aroma profiles and their connections to cannabis. This engaging chat highlights the significant role of New Zealand in the global hop landscape.
The genetic makeup of hop varieties fundamentally determines their flavor profiles, making genetics essential for brewers to understand hop characteristics.
Environmental factors like terroir, soil composition, and UV exposure significantly influence the unique aromas of New Zealand hops, showcasing regional differences.
Harvest timing is crucial in shaping hop aromas, as picking at different maturities can drastically alter the presence of specific aromatic compounds.
Deep dives
Understanding Hop Terroir
The concept of terroir in New Zealand hops plays a significant role in influencing the unique flavors and aromas that characterize these hops. Factors such as soil composition, geographic location, and climate contribute to distinct expressions of hop qualities. For example, soils in the Motueka area differ markedly from those in the Tapuera Valley, impacting how hops mature. These variances mean that even hops grown in close proximity can exhibit different sensory profiles due to their specific growing conditions.
Genetics and Hop Varieties
Genetics is a critical factor in determining the aromatic profiles of hop varieties, with a clear understanding that different hop types contribute distinct flavors. The podcast emphasizes that the innate characteristics of a hop, identified through genetic studies, cannot be altered by brewing methods alone. For instance, no matter how skillfully a brewer operates, a fuggle hop cannot be transformed into a nectar-like profile due to its genetic limitations. This genetic foundation creates a framework that strongly influences the potential for aroma and flavor in beer.
Impact of Harvest Timing
The timing of hop harvest is crucial, significantly affecting the aroma profiles of different hop varieties. A grower's decision to harvest early or late alters the aromatic compounds present, with late-picked varieties sometimes yielding strong onion or garlic aromas due to sulfur compounds. The podcast indicates that this maturity effect may outweigh the nuances of terroir in influencing flavor. Thus, brewers need to consider optimal pick windows closely to achieve the desired sensory characteristics in their hops.
The Role of Environmental Factors
Environmental stressors, particularly UV exposure, are suggested to contribute to the distinctive characteristics of New Zealand hops. The higher UV levels experienced in this region are believed to enhance the uniqueness of the hop aromas. Additionally, the podcast discusses how weather variability during the growing season can also impact the quality of the hops. Factors like prolonged sunshine or unexpected rainfall can create different biochemical responses in plants, further emphasizing the importance of local climate in hop production.
Practical Insights for Brewers
Brewers are encouraged to experience New Zealand hops firsthand to understand their unique flavors better. The podcast highlights several prominent hop varieties, such as Nelson Sauvin and Motueka, which can provide valuable insight into New Zealand’s hop character. For brewers unable to travel, they can still sample these hops at industry events, like the CBC, to rub and sniff various cultivars. This exposure will help brewers develop a mental lexicon for the specific sensory attributes associated with New Zealand hops, enhancing their brewing vocabulary and techniques.
Dr. Ron Beatson is the retired hop breeder who built a storied career at Plant & Food Research developing some of the most popular New Zealand hop varieties today, and Dr. Tom Shellhammer is the Oregon State University professor whose research into hop oils, hop terroir, hop-growing techniques, and more have made an indelible impact on the Pacific Northwest hop industry. Shellhammer is currently on a four-month sabbatical in New Zealand, studying the similarities and differences between U.S. and New Zealand hop practices, and presented at both the NZ Hops Harfest event (with Dr. Ron Beatson) and on his own at the Freestyle HopsHāpi Symposium.
In this episode, we brought the two together to discuss:
the hierarchy of impacts from genetics through terroir and agronomics
differences in hops within a farm or area versus differences between areas
the genesis of onion and garlic notes in hop aromas and flavors
sources of inconsistency in a hop variety
harvesting dynamics of Nelson Sauvin
cover crops in hop fields to promote soil health
multiple archetypes for hop varieties
the source of “diesel” and “dank” notes in hops and the crossovers with cannabis
thiol and terpene interactions in aroma formation over individual oil content
impact from lack of disease in New Zealand hop fields
soil and localized environmental impacts on New Zealand hop cultivation
And more.
This episode is brought to you by:
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