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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #385140
Research Project: Breeding, Genomics, and Integrated Pest Management to Enhance Sustainability of U.S. Hop Production and Competitiveness in Global Markets

Location: Forage Seed and Cereal Research Unit

Title: Nitrogen fertility practices in the field influence the accumulation of nitrate during the production of hop-forward beer

Author
item SHELLHAMMER, THOMAS - Oregon State University
item LAFONTAINE, SCOTT - Oregon State University
item ISKRA, ANNE - Oregon State University
item CLAWSON, JEFF - Oregon State University
item Trippe, Kristin
item Phillips, Claire
item Gent, David - Dave

Submitted to: BrewingScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/2021
Publication Date: 9/1/2021
Citation: Shellhammer, T.H., Lafontaine, S.R., Iskra, A.E., Clawson, J., Trippe, K.M., Phillips, C.L., Gent, D.H. 2021. Nitrogen fertility practices in the field influence the accumulation of nitrate during the production of hop-forward beer. BrewingScience. 74:88-91. https://doi.org/10.23763/BrSc21-08shellhammer.
DOI: https://doi.org/10.23763/BrSc21-08shellhammer

Interpretive Summary: Nitrate is a naturally occurring compound, but is undesirable at elevated levels. Certain literature suggests that dietary sources of nitrate should be moderated. Hops and malt are the two main sources of nitrate in beer, with hops being the main source in beers that are late-hopped or dry-hopped. In this research, we documented that nitrogen fertilization practices during hop production is correlated with nitrate levels in hop-forward beers. Nitrate accumulation following each hop addition was associated with nitrate concentration of the hops used and, ultimately, the rate of nitrogen fertilizer applied in the field. Although beer is a minor dietary source of nitrate, our results indicate that reducing nitrogen fertilization rates in the field can reduce nitrates in hop-forward beers.

Technical Abstract: Hops and malt are the two main sources of nitrate in beer, with hops being the main source in beers that are late-hopped or dry-hopped. We characterized how nitrogen fertilizer dose applied in the field during hop production influences nitrate accumulation in hop-forward beers. Two contrasting nitrogen fertilizer rates, 90 and 269 kg/ha, were used to produce hops that differed in their nitrate concentrations (852 and 2651 mg/kg of nitrate, respectively) to quantify the dose-response relationship. Hop-forward beers (kettle hopped at 0.52 g/L, whirlpool hopped at 2 g/L, and dry-hopped at 4 g/L) were produced with these hops and nitrate accumulation was quantified after each hop addition. Nitrate accumulation following each hop addition was associated with nitrate concentration of the hops and, ultimately, the rate of nitrogen fertilizer applied in the field. As supported by previous studies, nitrate accumulated quantitatively with hop addition, with dry-hopping resulting in the largest increase in nitrate, followed by whirlpool additions, and then kettle hop additions. Although beer is a minor dietary source of nitrate, our results indicate that reducing nitrogen fertilization rates in the field can reduce nitrates in hop-forward beers.