Productivity of immobilized yeast reactors with very high gravity worts

Ilkka Virkajärvi (Corresponding Author), Marko Vainikka, Hannele Virtanen, Silja Home

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In the competitive world of beer production, efficient utilization of raw materials and equipment together with smooth operation are advantageous. In this study, data from laboratory-scale main fermentations with original gravities between 15 and 24°P and immobilized yeast are presented. The worts were prepared from malt extract, and lower original gravities were obtained by diluting the 24°P wort with brewery water. The yeast strain used was a production strain from a brewery. Porous glass beads were used as the carrier. The optimal gravity found in regard to ethanol productivity was between 18 and 21°P. The highest ethanol concentration in the beers was over 10% (v/v). The aroma compound profiles of the beers produced were quite similar, except for acetaldehyde. The laboratory-scale fermentations using immobilized yeast may be an effective tool to screen for ethanol-tolerant strains or to find process parameters that facilitate very-high-gravity brewing.
Original languageEnglish
Pages (from-to)188-197
JournalJournal of the American Society of Brewing Chemists
Issue number4
Publication statusPublished - 2002
MoE publication typeA1 Journal article-refereed



  • Beer, Fermentation

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