Joint fermentation of at least two but often more grape varieties. In contrast to the Mixed Set, this is not an inevitable consequence as in the Mixed Set, but is achieved by appropriate joint processing of grapes from different vineyards. The technique of mixed fermentation comes from France, where the red wine Côte Rôtie is made from white and red grapes. In the past, Chianti was also produced in this way, but today it is rarely practised. Since the beginning of the new millennium this form has been used more and more, especially in Australia and New Zealand.
Mixed fermentation emphasises the floral aromas and improves colour intensity and colour stability, which has been confirmed by research at the University of California in Davis. The blending of several varieties can be done in different ways. Either the whole grapes are pressed together or (especially for white grapes) the already destemmed grapes or the pressed grape must is added to the other grapes. The mixed fermentation or the resulting grape cuvée is in contrast to the classic cuvée, where mostly already fermented wines are assembled.