Late Harvest Wine - Noble Rot

Noble Rot

Botrytis cinerea is a fungus that affects many wine grapes and causes them to shrivel into moldy raisins. The fungus responds to the humidity and warmth in the climate and attacks the grapes. As the mold penetrates the skin its spores begin to germinate, causing the water inside to evaporate and the grape to dehydrate. With the absence of water, the sugar becomes more concentrated and the botrytis begins to alter the acidity within the grape. Typically botrytis infection begins to take place in late September and can last till late October. In some years desiccation may occur leaving tiny amount of sweet liquor like juice within the grape.

The infection rate of botrytis is sporadic with vines and bunches achieving full rottenness at different times. This requires harvest workers to go through the vineyards several times between October and November to hand-pick the full rotted grapes. In some occasions, the usable grapes from a single vine may only produce enough juice for a single glass.