What Is Noble Rot?
But not just any mould – Botrytis cinerea sucks water out of the grape whilst imparting new flavours of honey and apricot to the future wine.
However, it may also release metabolites that can really mess up the fermentation process – in fact, Recioto Della Valpolicella from Italy relies on a premature stop to fermentation to keep it sweet, otherwise it becomes the dry wine Amarone.
Unfortunately, the fungus is very fussy about the conditions required for such ‘noble rot’, if it is too damp the same fungus causes the destructive ‘grey rot’. So winemakers walk a fine line between maximising the amount of noble rot and losing the whole crop to grey rot.
Typically noble rot forms best in conditions where morning mist from a nearby lake or the sea gets burnt off during the day by the hot sun. That is such a wine ‘thing’ isn’t it…
The wait for noble rot to form is the reason why noble rot wines are usually late-harvested.
No doubt the first noble rot wines were created by accident – both the Hungarians and the Germans have similar stories of how the harvest was delayed for some reason, but the mouldy grapes were used anyway and then found to be delicious.
Noble rot is responsible for many of the greatest dessert wines if you are lucky enough to drink one. It feels as though you are drinking liquid gold. Seriously, try for your self.