Comparing the Effect of Yeast Inoculation Rate on Fermentation Kinetics, Chemical and Aroma Compounds in Cider Fermentations

Date & Time: Thursday, January 18, 2:00-3:15 PM

Cost: $12 SOLD OUT!

Speakers: Jocelyn Kuzelka & Andy Hannas

Yeast produce different types and concentrations of aroma compounds as a function of yeast strain type, fermentation conditions, raw ingredients, and juice treatments. The sensory profile of cider is significantly associated with yeast selection and the quality of cider is dependent upon predictable fermentation outcomes. During yeast metabolism subtle changes in yeast cell inoculum level, determine rate of cell division, nitrogen demand, and availability of aroma precursors. It is generally accepted in the wine world, that 106 yeast cells/mL should allow the fermentation to proceed predictably and completely with little to no residual sugar remaining; while under inoculating leads to sluggish and stuck fermentations. However, recent research in wine and beer has suggested that yeast inoculation rate can be used to drive aroma production toward an increase in positive aromas. Speakers in this advanced level sensory session will explore the effect of yeast inoculum size on the production of aroma compounds both positive and negative in a cider fermentation, by decreasing cell count to accommodate the limited carbohydrate and nitrogen present in apple juice destined for fermentation. Attendees will learn more about yeast metabolism and how yeast inoculation rates can be used to drive cider style and quality.