its very difficult to tell the stage of evolution of a wine by its aroma, on the palate yes, however we can certainly tell if the wine is young or old vintage by its nose or color.
on the palate, its still the feeling of tannin, acidity and fruit if there are in harmony, an experienced wine taster can tell from the sense of each vital component whether the wine is very young (premature), getting there, fully matured or going downhill, however the most difficult part is to tell if the wine is at its peak, because before the wine goes down no one can tell it had reached it peak.
