Interaction between Cork and Yeast: Application to Sparkling Wine Processing

Abstract

An innovative method has been developed to observe yeasts at the surface of cork using two-photon microscopy and to foresee if a removable crown cap substitution by two disc cork stopper may impact the bottle fermentation during sparkling wine processing. Indeed, while much of the Champagne wine industry is using crown seals for tirage and ageing, some producers are choosing cork closures, particularly for Champagne wines subject to longer ageing periods. The developed technique is based on the cork autofluorescence and on DAPI labelling of yeasts with a different emission wavelength range. This study has been performed for cork in contact with model wine and in bottle with Champagne wine, following the fermentation and the maturation over one year. For both cases, neither biofilm nor strong adhesion of yeast cells was detected on the cork surface. However, in the case of Champagne wine, a small amount of yeasts was observed in the empty cavities of the cork cell structure. Since the development of yeasts on the cork surface remains very limited, cork stoppers with discs can be used during Champagne wine processing instead of removable caps without being afraid of cork as a potential fermentation support.