Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains
Previous research has shown that hops contain enzymes able to hydrolyze unfermentable dextrins into fermentable sugars when added during the dry-hopping process. In the presence of live yeast, these additional fermentable sugars can lead to an over-attenuation of the beer; a phenomenon known as “hop...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-04-01
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| Series: | Fermentation |
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| Online Access: | https://www.mdpi.com/2311-5637/7/2/66 |
| _version_ | 1797535829839577088 |
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| author | James Bruner Andrew Marcus Glen Fox |
| author_facet | James Bruner Andrew Marcus Glen Fox |
| author_sort | James Bruner |
| collection | DOAJ |
| description | Previous research has shown that hops contain enzymes able to hydrolyze unfermentable dextrins into fermentable sugars when added during the dry-hopping process. In the presence of live yeast, these additional fermentable sugars can lead to an over-attenuation of the beer; a phenomenon known as “hop creep”. This study attempts to analyze the effect of different <i>Saccharomyces</i> yeast species and strains on hop creep, with the intent to find an ability to mitigate the effects of dry-hop creep by using a specific yeast. Thirty different yeast species and strains were chosen from commercial and academic collections and propagated for pilot fermentations. Brews were performed at the Anheuser-Busch Research Brewery (1.8 hL, 10 °P, 20 IBU) at UC Davis and split to 40 L cylindroconical fermenters, with one fermenter in each yeast pair receiving 10 g/L Centennial hop pellets towards the end of fermentation. Standard analytical measurements were performed over the course of fermentation, with real degrees of fermentation (RDF) and extract measured on an Anton Paar alcolyzer. In order to preemptively determine the amount of hop creep to be experienced with each unknown fermentation, bench-top fermentations with 20 g/L dry-hops were performed concurrently and compared to the pilot scale fermentations. RDF was significantly higher (<i>p</i> < 0.01) on dry-hopped than non-dry-hopped fermentations beginning two days post dry-hopping to the end of fermentation, with the exceptions of SafAle™ BE-134, a <i>S. cerevisiae</i> var. <i>diastaticus</i>, and UCDFST 11-510, a <i>S. mikatae</i>. No apparent correlation between flocculation and increased RDF was shown in dry-hopped treatments. pH was significantly different between the dry-hopped and non-hopped fermentations (<i>p</i> < 0.05 one day post dry-hop, <i>p</i> < 0.01 for all subsequent days); this may have impacted on additional attenuation. No yeasts in this study indicated their use for mitigation of dry-hop creep, but this is a first look at beer fermentation for some of the chosen yeasts. The results also present a new perspective on how hop creep varies in fermentation. |
| first_indexed | 2024-03-10T11:50:53Z |
| format | Article |
| id | doaj.art-2be4e778b8da4d24880aa68af1cf7cd1 |
| institution | Directory Open Access Journal |
| issn | 2311-5637 |
| language | English |
| last_indexed | 2024-03-10T11:50:53Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fermentation |
| spelling | doaj.art-2be4e778b8da4d24880aa68af1cf7cd12023-11-21T17:41:26ZengMDPI AGFermentation2311-56372021-04-01726610.3390/fermentation7020066Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and StrainsJames Bruner0Andrew Marcus1Glen Fox2Food Science and Technology Department, University of California, 1 Shields Ave, Davis, CA 95616, USAFood Science and Technology Department, University of California, 1 Shields Ave, Davis, CA 95616, USAFood Science and Technology Department, University of California, 1 Shields Ave, Davis, CA 95616, USAPrevious research has shown that hops contain enzymes able to hydrolyze unfermentable dextrins into fermentable sugars when added during the dry-hopping process. In the presence of live yeast, these additional fermentable sugars can lead to an over-attenuation of the beer; a phenomenon known as “hop creep”. This study attempts to analyze the effect of different <i>Saccharomyces</i> yeast species and strains on hop creep, with the intent to find an ability to mitigate the effects of dry-hop creep by using a specific yeast. Thirty different yeast species and strains were chosen from commercial and academic collections and propagated for pilot fermentations. Brews were performed at the Anheuser-Busch Research Brewery (1.8 hL, 10 °P, 20 IBU) at UC Davis and split to 40 L cylindroconical fermenters, with one fermenter in each yeast pair receiving 10 g/L Centennial hop pellets towards the end of fermentation. Standard analytical measurements were performed over the course of fermentation, with real degrees of fermentation (RDF) and extract measured on an Anton Paar alcolyzer. In order to preemptively determine the amount of hop creep to be experienced with each unknown fermentation, bench-top fermentations with 20 g/L dry-hops were performed concurrently and compared to the pilot scale fermentations. RDF was significantly higher (<i>p</i> < 0.01) on dry-hopped than non-dry-hopped fermentations beginning two days post dry-hopping to the end of fermentation, with the exceptions of SafAle™ BE-134, a <i>S. cerevisiae</i> var. <i>diastaticus</i>, and UCDFST 11-510, a <i>S. mikatae</i>. No apparent correlation between flocculation and increased RDF was shown in dry-hopped treatments. pH was significantly different between the dry-hopped and non-hopped fermentations (<i>p</i> < 0.05 one day post dry-hop, <i>p</i> < 0.01 for all subsequent days); this may have impacted on additional attenuation. No yeasts in this study indicated their use for mitigation of dry-hop creep, but this is a first look at beer fermentation for some of the chosen yeasts. The results also present a new perspective on how hop creep varies in fermentation.https://www.mdpi.com/2311-5637/7/2/66yeast<i>Saccharomyces</i>fermentationbeerdry-hoppinghop creep |
| spellingShingle | James Bruner Andrew Marcus Glen Fox Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains Fermentation yeast <i>Saccharomyces</i> fermentation beer dry-hopping hop creep |
| title | Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains |
| title_full | Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains |
| title_fullStr | Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains |
| title_full_unstemmed | Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains |
| title_short | Dry-Hop Creep Potential of Various <i>Saccharomyces</i> Yeast Species and Strains |
| title_sort | dry hop creep potential of various i saccharomyces i yeast species and strains |
| topic | yeast <i>Saccharomyces</i> fermentation beer dry-hopping hop creep |
| url | https://www.mdpi.com/2311-5637/7/2/66 |
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