Sherry wines velum

Martinez, R, Perez Rodriguez, L., Benitez, T. (1997b). Eactors which affect velum formation by flor yeasts isolated from sherry wine. Syst. App. Microbiol., 20, 154-157. 

In this study, commercial Fino sherry wines (5 years of biological ageing) which were selected by expert tasters as more representative were used. Also, selected strains of S. cerevisiae and S, bayamis (Kurtzman Fell, 1998) were used. These yeast strains, corresponding to the S. cerevisiae capensis and bayanus races in the Kreger-van Rij classification (1984), were isolated from a velum of industrial wine produced in the Montilla-Moriles region. The criteria and tests for their selection have been reported in previous papers (Guijo et al., 1986 Moreno et al., 1991). 

As noted previously, the main types of sherry (fino, oloroso, and amon-tillado) are produced employing different conditions. These differences result in significantly different polyphenolic composition. In the case of fino-type sherries, the layer of yeast that grows in the surface of the wine (flor velum) preserves its pale color. The velum limits the exposure of the wine from oxygen (Baron et ah, 1997). Hence, fino wines mature in a markedly reductive environment. 

---