PT  - JOURNAL ARTICLE
AU  - David J. Killeen
AU  - Roger Boulton
AU  - André Knoesen
TI  - Advanced Monitoring and Control of Redox Potential in Wine Fermentation
AID  - 10.5344/ajev.2018.17063
DP  - 2018 May 29
TA  - American Journal of Enology and Viticulture
PG  - ajev.2018.17063
4099  - http://www.ajevonline.org/content/early/2018/05/23/ajev.2018.17063.short
4100  - http://www.ajevonline.org/content/early/2018/05/23/ajev.2018.17063.full
AB  - The reduction-oxidation potential, or redox potential, in a fermenting juice can influence the reactions both in the juice and those within the yeast cells during wine fermentations. The ability to monitor and control the redox potential at a chosen value by adding air during a red wine fermentation was demonstrated in triplicate at the 100L scale. The Brix curves and reduction-oxidation potential patterns in the controlled fermentations were compared to those in the un-aerated fermentations. The redox control system consisted of a commercial pH meter with a reduction-oxidation electrode and a custom-designed electronic controller. The study showed the reduction-oxidation potential could be controlled at 215 mV, well above its natural level throughout the fermentation. The reduction-oxidation potential control resulted in both faster peak fermentation rates and an earlier completion of the wine fermentations. The analysis of these fermentation curves by a mathematical model indicates that both yeast cell viability and the specific maintenance rate of the viable cells were significantly increased by controlling the redox potential during the fermentation.