RT Journal Article SR Electronic T1 Rehydration Protocols for Active Dry Wine Yeasts and the Search for Early Indicators of Yeast Activity JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 474 OP 480 DO 10.5344/ajev.2006.57.4.474 VO 57 IS 4 A1 Virginie Soubeyrand A1 Anne Julien A1 Jean-Marie Sablayrolles YR 2006 UL http://www.ajevonline.org/content/57/4/474.abstract AB It is widely accepted that active dry wine yeasts (ADY) must be rehydrated before addition to musts. Current rehydration procedures are over 15 years old and may not be optimal for the approximately 200 strains commercially available worldwide. Temperature, water hardness, sugar concentration, agitation, and rehydration duration did not have a major effect on the recovery of fermentative activity in three yeast strains differing in rehydration behavior and/or lag phase. Early indicators of yeast activity during rehydration were then investigated. We correlated pH, carbon dioxide release, and trehalose utilization with the early stage of fermentation. Results showed that the recovery of fermentative activity by ADY can be measured early and easily by rehydration indicators, particularly changes in pH and carbon dioxide release.