Late harvest wine

Late harvest is a term applied to wines made from grapes left on the vine longer than usual. Late harvest is usually an indication of a sweet dessert wine, such as late harvest Riesling. Late harvest grapes are often more similar to raisins, but have been naturally dehydrated while on the vine.

Botrytis cinerea, or noble rot, is a mold that causes grapes to lose nearly all of their water content. Wines made from botrytis-affected grapes are generally very sweet.

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.