Comparative study of wine composition in Pinot Noir spontaneously fermented in vineyard and in winery

Abstract

Background and Aims: Spontaneous fermentation is driven by a complex community of indigenous yeasts originating from the vineyard which are considered as part of the terroir. Saccharomyces cerevisiae has been reported as the most abundant yeast in winery according to previous studies. Thus, our hypothesis of this study was that spontaneous fermentation in vineyard would be a better expression of terroir and reflection of the vintage.

Methods and Results: Pinot Noir grapes from same vineyard have been spontaneously fermented in vineyard and in winery respectively in 2015 and 2016. Compared with winery fermentation, wines fermented in vineyard consistently showed significantly lower level of colour density, total red pigments, total phenolics, and tannin. Wines made in 2016 also showed significantly lower level of colour density, red pigments and total phenolics, but no difference in tannin. Phenolic composition analysis by HPLC showed Pinot Noir fermented in vineyard had significantly lower level of a range of benzoic acids and flavonoids.

Conclusion: Pinot Noir fermented in vineyard consistently showed lower level extraction of colour and phenolic substances, which is likely due to the variance in yeast population and dynamics during fermentation. Significance of study: This preliminary study could help us better understand the role of wild yeasts in shaping regional characteristics in wine. Further studies will be conducted on aroma profiling of resultant wines and analysing the changes in yeast population and dynamics during fermentation.

Significance of study: This preliminary study could help us better understand the role of wild yeasts in shaping regional characteristics in wine. Further studies will be conducted on aroma profiling of resultant wines and analysing the changes in yeast population and dynamics during fermentation.