CHANGES IN GRAPE MATURITY INDUCED BY SPRAYING ETHANOL

Three different ethanol solutions were sprayed onto Cabernet Sauvignon (Vitis vinifera L.) clusters during the ripening period: 2.5, 5 and 10% by volume in water.
Controls were sprayed with water alone.
Three different times of spraying were also tested: 8, 10 and 13 weeks post-flowering.
One of the observed changes was a lower titratable acidity in grape samples at harvest, when the clusters were sprayed with ethanol at 10 weeks, in comparison with controls.
The wines made with grapes treated with ethanol after mid-veraison, had higher ODs at 520 nm than did the controls.
This may due to a combined effect of red pigment levels and acidity.
In addition, following malolactic fermentation, the acidity levels of wines made with ethanol-treated grapes were slightly higher than those made with the control grapes.
Spraying ethanol at 13 weeks post-flowering increased the berry weight by 10% at harvest without decreasing the °Brix value.
The corresponding wines had similar degrees of alcohol.
This observation was made for the first time in 2001.

XXVI International Horticultural Congress: Viticulture – Living with Limitations

C. Chervin, A. El Kereamy, V. Renouf, C. Rohmer, A. Roques, P. Garin, L. Guichaoua, M. Sanvoisin, J.P. Roustan, S. Savocchia, R. van Heeswijck

acidity, berry weight, Cabernet Sauvignon, anthocyanin, wine

https://doi.org/10.17660/ActaHortic.2004.640.35