Definition: Phenolic ripening

The current study of Gamaret ripening is based on French theories. The quality of tannins in relation to the degree of grape ripeness is the subject of a four-year study launched in Changins this autumn (2003) in collaboration with fifteen wine estates throughout French-speaking Switzerland. It initially concerns Gamaret. Sugar is not a universal indicator of ripeness, but analysing the ripeness of red polyphenols is a more accurate parameter. Specialists measure anthocyanins, molecules considered to be markers, in the laboratory. When the curve measuring the sugar content in the grapes reaches its maximum and stabilises, the anthocyanin content continues to evolve. The aim is therefore to determine the ideal waiting time after the maximum sugar level has been reached in order to obtain a certain type of wine, in this case, more woody reds, which are popular with consumers today. The analyses provide two pieces of information: the ease with which the grape releases its colour and, by analogy, the progress of tannin maturity. The idea is not to achieve standardisation, but to take characteristics into account in relation to a theory. Bordeaux wines have been produced on this same principle for a number of years. Switzerland, which is not accustomed to producing tannic red wines, therefore wants to gather knowledge about its terroir and grape varieties. The data collected is intended to be read in parallel with that of the terroir study that has been underway for a year now (status 08/2003).