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.

Harvest (wine)

The harvesting of wine grapes (Vintage) is one of the most crucial steps in the process of winemaking. The time of harvest is determined primarily by the ripeness of the grape as measured by sugar, acid and tannin levels with winemakers basing their decision to pick based on the style of wine they wish to produce. The weather can also shape the timetable of harvesting with the threat of heat, rain, hail, and frost which can damage the grapes and bring about various vine diseases. In addition to determining the time of the harvest, winemakers and vineyard owners must also determine whether to use hand pickers or mechanical harvesters. The harvest season typically falls between August & October in the Northern Hemisphere and February & April in the Southern Hemisphere. With various climate conditions, grape varieties, and wine styles the harvesting of grapes could happen in every month of the calendar year somewhere in the world. In the New World it is often referred to as the crush.