Download The Biotechnology of Sparkling Wines ABSTRACT

The Biotechnology of Sparkling Wines
Steve DiFrancesco, Winemaker, Glenora Wine Cellars
ABSTRACT
Sparkling wines have effervescence from naturally produced CO2 that
results from the metabolism of sugar by yeasts. The other major
byproduct of this yeast fermentation is ethanol. In addition, there are
numerous byproducts, often found in tiny quantities, that affect the
flavors of the wine, as well as the quality of the bubbles. There is more
than one method of capturing the CO2 in the product, the most
famous being the methode champenoise used for Champagne in
France, as well as in other famous wine producing regions in the world.
The Champagne method emphasizes extended aging in contact with the yeasts that die soon after the
sugars have been consumed. After cell death, the autolysis of the cells eventually releases low molecular
weight compounds such as amino acids, proteins, glucans and lipids. These compounds are key quality
indicators of high quality, usually expensive, Champagnes and sparkling wines.
BIOGRAPHY
Steve DiFrancesco earned a BS in Biology from Stetson University, DeLand, Fla. in 1978. He became
fascinated with wine while working at a high-end restaurant during college. After graduation he became
a lab technician at Gold Seal Vineyards, a large winery owned by Seagrams, that eventually became part
of Constellation Brands. He worked at Bully Hill Vineyards, then became Assistant Winemaker at Glenora
Wine Cellars. He became Winemaker at Lucas Vineyards, then returned to Glenora as Winemaker in
1995. The owners of Glenora purchased Knapp Vineyards, and Steve is responsible for wine quality for
both brands.