The effects of enological practices in anthocyanins, phenolic compounds and wine colour and their dependence on grape characteristics

The effect of three different techniques in flavonoid and non-flavonoid compounds were tested on a Monastrell wine elaborated in 2003 looking for an improvement of wine colour and its stability. These techniques involved running-off part of the must prior to fermentation, the use of a macerating enzyme or an enological tannin, and they were selected for showing good results on wine chromatic characteristics after a previous two years of study. The wine produced by running-off part of the juice had the highest colour intensity during the first steps of winemaking, but it showed very low stability and, at the moment of bottling, a dramatic decrease in colour was observed. At this moment and during bottle aging, the wine treated with enological tannin showed the best chromatic characteristics and stability. The results are not coincident with those observed the previous years, indicating the important role played by the grape characteristics at the moment of harvest on the effectiveness of an enological practice for improving wine colour.