MacKinnon D., Pavlovič V., Čeh B., Naglič B., Pavlovič M. (2020): The impact of weather conditions on alpha-acid content in hop (Humulus lupulus L.) cv. Aurora. Plant Soil Environ., 66: 519–525.
The influence of four main weather attributes on the content of alpha-acids of the hop cv. Aurora for the period 1994–2019 was studied. By analysing correlation coefficients, specific times of the year when the weather conditions affect the alpha-acid content with the goal of creating a forecasting model in Slovenia were identified. The most significant periods of weather that impacted the alpha-acid contents throughout the growing time of year are recognised as attributes of temperatures (T), rainfall (R) and sunshine (S) calculated from the 25th to 30th week (T2530, r = –0.78, P < 0.01; R2529, r = 0.72, P < 0.01 and S2529, r = –0.81, P < 0.01) and attributes of relative humidity (RH) from the 27th to 32nd week (RH2732, r = 0.82, P < 0.01). T2530 stands for the amount of active temperatures from June 18 to July 29. Likewise, R2530 matches to the precipitation (in mm or L/m2) during the same time period.
hop quality; α-acids; brewing process; biosynthesis; vegetative period
Abdi H. (2003): Factor rotations in factor analyses. In: Lewis-Beck M.S., Bryman A., Liao T.F. (eds.): The SAGE Encyclopedia of Social Science Research Methods. Thousand Oaks, SAGE Publications, Inc. ISBN: 9780761923633
Analytica EBC (2000): European Brewery Convention. Grundwerk: Section 7.4. EBC Analysis Committee. Nuernberg, Hans Carl Getraenke Fachverlag.
De Keukeleire J., Janssens I., Heyerick A., Ghekiere G., Cambie J., Roldán-Ruiz I., Van Bockstaele E., De Keukeleire D. (2007): Relevance of organic farming and effect of climatological conditions on the formation of α-acids, β-acids, desmethylxanthohumol, and xanthohumol in hop (Humulus lupulus L.). Journal of Agricultural and Food Chemistry, 55: 61–66. https://doi.org/10.1021/jf061647r
Donner P., Pokorný J., Ježek J., Krofta K., Patzak J., Pulkrábek J. (2020): Influence of weather conditions, irrigation and plant age on yield and alpha-acids content of Czech hop (Humulus lupulus L.) cultivars. Plant, Soil and Environment, 66: 41–46. https://doi.org/10.17221/627/2019-PSE
Hecht S., Kammhuber K., Reiner J., Bacher A., Eisenreich W. (2004): Biosynthetic experiments with tall plants under field conditions. 18O2 incorporation into humulone from Humulus lupulus. Phytochemistry, 65: 1057–1060. https://doi.org/10.1016/j.phytochem.2003.08.026
Košir I.J., Livk J. (2019): Hop Industry Crop Evaluation 2019. Žalec, Slovenian Institute of Hop Research and Brewing. Contract No. 2311-09-000136, 14. (In Slovene)
Kučera J., Krofta K. (2009): Mathematical model for prediction of alpha acid contents from meteorological data for ‘Saaz’ aroma variety. ISHS Acta Horticulturae, 848: 131–139. https://doi.org/10.17660/ActaHortic.2009.848.14
Moir M. (2000): Hops – a millennium review. Journal of the American Society of Brewing Chemists, 58: 131–146. https://doi.org/10.1094/ASBCJ-58-0131
Možný M., Tolasz R., Nekovar J., Sparks T., Trnka M., Žalud Z. (2009): The impact of climate change on the yield and quality of Saaz hops in the Czech Republic. Agricultural and Forest Meteorology, 149: 913–919. https://doi.org/10.1016/j.agrformet.2009.02.006
Pavlovič M., Čerenak A., Pavlovič V., Rozman Č., Pažek K., Bohanec M. (2011): Development of DEX-HOP multi-attribute decision model for preliminary hop hybrids assessment. Computers and Electronics in Agriculture, 75: 181–189. https://doi.org/10.1016/j.compag.2010.11.002
Pavlovič V., Pavlovič M., Čerenak A., Košir I.J., Čeh B., Rozman Č., Turk J., Pažek K., Krofta K., Gregoric G. (2012): Environment and weather influence on quality and market value of hops. Plant, Soil and Environment, 58: 155–160. https://doi.org/10.17221/499/2011-PSE
Srečec S., Kvaternjak I., Kaučić D., Špoljar A., Erhatič R. (2008): Influence of climatic conditions on accumulation of α-acids in hop clones. Agriculturae Conspectus Scientificus, 73: 161–166.
Srečec S., Čeh B., Ciler T.S., Rus A.F. (2013): Empiric mathematical model for predicting the content of alpha-acids in hop (Humulus lupulus L.) cv. Aurora. Springer Plus, 2: 59. https://doi.org/10.1186/2193-1801-2-59
Steenackers B., De Cooman L., De Vos D. (2015): Chemical transformations of characteristic hop secondary metabolites in relation to beer properties and the brewing process: a review. Food Chemistry, 172: 742–756. https://doi.org/10.1016/j.foodchem.2014.09.139