Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers
This paper reports the effects of dry-hopping at 4 and 19 °C for a low alpha versus high alpha hop variety on the resulting profiles of non-volatile hop acids (humulinones, iso-a-acids, a-acids). In a dry-hopping study conducted over 2 weeks, we found a significant increase in humulinone concentrati...
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| Format: | Article |
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Fachverlag Hans Carl GmbH
2017
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| Online Access: | https://eprints.nottingham.ac.uk/49491/ |
| _version_ | 1848798009575342080 |
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| author | Oladokun, O. James, S. Cowley, T. Smart, K. Hort, J. Cook, D. |
| author_facet | Oladokun, O. James, S. Cowley, T. Smart, K. Hort, J. Cook, D. |
| author_sort | Oladokun, O. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | This paper reports the effects of dry-hopping at 4 and 19 °C for a low alpha versus high alpha hop variety on the resulting profiles of non-volatile hop acids (humulinones, iso-a-acids, a-acids). In a dry-hopping study conducted over 2 weeks, we found a significant increase in humulinone concentration driven principally by hop alpha acid content and the duration of dry-hopping. Conclusive evidence of iso-a-acid losses during dry-hopping (by adsorption onto spent hops) is presented, in addition to a significant increase in a-acid concentrations, which was observed only for beers dry-hopped at 19 °C with the high alpha hop variety. Measured beer parameters (especially at 19 °C) revealed an increase in pH, ABV (%), and a decrease in beer density during dry-hopping - from which we conclude that further attenuation of beer occurred during dry-hopping. The polyphenol content of beers was found to increase substantially with dry-hopping time, whilst both temperature and hop variety were found to be significant factors determining the amounts of polyphenols extracted. Finally, analysis of the spent hop slurry (recovered after 14 days of dry-hopping) confirmed that the residual content of hop acids (a-acids, their oxidised derivatives and polyphenol content), makes these materials - currently treated as waste - of potential value for re-use in the brewing process. |
| first_indexed | 2025-11-14T20:12:57Z |
| format | Article |
| id | nottingham-49491 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T20:12:57Z |
| publishDate | 2017 |
| publisher | Fachverlag Hans Carl GmbH |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-494912020-05-04T19:19:57Z https://eprints.nottingham.ac.uk/49491/ Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers Oladokun, O. James, S. Cowley, T. Smart, K. Hort, J. Cook, D. This paper reports the effects of dry-hopping at 4 and 19 °C for a low alpha versus high alpha hop variety on the resulting profiles of non-volatile hop acids (humulinones, iso-a-acids, a-acids). In a dry-hopping study conducted over 2 weeks, we found a significant increase in humulinone concentration driven principally by hop alpha acid content and the duration of dry-hopping. Conclusive evidence of iso-a-acid losses during dry-hopping (by adsorption onto spent hops) is presented, in addition to a significant increase in a-acid concentrations, which was observed only for beers dry-hopped at 19 °C with the high alpha hop variety. Measured beer parameters (especially at 19 °C) revealed an increase in pH, ABV (%), and a decrease in beer density during dry-hopping - from which we conclude that further attenuation of beer occurred during dry-hopping. The polyphenol content of beers was found to increase substantially with dry-hopping time, whilst both temperature and hop variety were found to be significant factors determining the amounts of polyphenols extracted. Finally, analysis of the spent hop slurry (recovered after 14 days of dry-hopping) confirmed that the residual content of hop acids (a-acids, their oxidised derivatives and polyphenol content), makes these materials - currently treated as waste - of potential value for re-use in the brewing process. Fachverlag Hans Carl GmbH 2017-11-30 Article PeerReviewed Oladokun, O., James, S., Cowley, T., Smart, K., Hort, J. and Cook, D. (2017) Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers. BrewingScience, 70 (6). pp. 187-196. ISSN 1613-2041 dry-hopping humulinones "hop-creep" bitterness quality spent hops hop polyphenols http://www.brewingscience.de/index.php?tpl=table_of_contents&year=2017&edition=0011%2F0012&article=90607 |
| spellingShingle | dry-hopping humulinones "hop-creep" bitterness quality spent hops hop polyphenols Oladokun, O. James, S. Cowley, T. Smart, K. Hort, J. Cook, D. Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| title | Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| title_full | Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| title_fullStr | Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| title_full_unstemmed | Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| title_short | Dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| title_sort | dry-hopping: the effects of temperature and hop variety on the bittering profiles and properties of resultant beers |
| topic | dry-hopping humulinones "hop-creep" bitterness quality spent hops hop polyphenols |
| url | https://eprints.nottingham.ac.uk/49491/ https://eprints.nottingham.ac.uk/49491/ |