Several publications can be found for the determination of phenolic compounds in grapes, musts and wines, and particulary red wines
little attention seems to have been paid to the non-coloured phenolic acids in white varietal grapes that grow in Portugal. Thus, this work examine the changes of eight phenolic acids in white wines manufactured with cultivars of three important white varieties that grew in
1996 in the Douro region. Preliminary data on the variation of these compounds due to eects of the level of maturation of the grapes and of conditions of fermentation are also reported.