In this study the highest Pb concentrations in wine
were found in cava and oloroso sherry (Table 4). A high
Pb content in oloroso sherry was also observed in a
previous study (Lopez-Artiguez et al., 1990). The
elevated levels of Pb in cava may be due to the acidity
of this type of wine and to the presence of CO2. High
concentrations of Pb were found in red wines, probably
because the lees remain in prolonged contact with must.
In addition, dark grapes usually contain higher concentrations
of Pb than white grapes (Marin and Ostapczuk,
1992). The high concentrations of sulfur dioxide in
these wine samples may also affect Pb content. The
differences between Pb levels between white and rose
wines were not statistically significant, although Pb
levels were higher in some of the white wines. During
white wine-making, Pb is probably removed when grape
skins and lead-attracting yeasts on the skins are
eliminated prior to fermentation; this is not done in red
wine vinification.