Winemaking Terms Defined: In the Vineyard—Life Cycle of a Grape

Here are some terms that describe the stages of grape development throughout a year (note that terms are in chronological order):

Note: Dates given are for the Northern Hemisphere only.

budbreak  the first sign of spring growth when tiny green shoots become visible on a vine. Also known as budburst. Occurs in early spring, around March.

flowering  production of flowers, which must be pollinated in order to produce fruit. Most vinifera vines can self-pollinate, while other grapes may need to be pollinated from other vines by wind or insects. Occurs around May.

fruit set  the stage of growth where the flowers, after pollination, start to develop into berries. Occurs around May. 

véraison  (veh-RYE-zun) the stage of growth when the fruit starts to change to its final color. At this point the berries are about half their final size, are high in acid and contain hardly any sugar. Occurs around the end of July into August.

ripeness  the final stage of growth around September or October when grapes have achieved the following:

physiological ripeness the ripening of substances in the grapes other than sugar, such as tannin (wines with insufficient tannin and other phenolic compounds taste “green”), tartaric acid (affects pH) and others. One sign of physiological ripeness is a change in the seeds’ color from green to yellow.

sugar ripeness  the condition where grapes reach a certain sugar concentration, measured in degrees Brix.

harvest  removal of the grapes from the vines, either by hand or by mechanical harvesters. Because it is ideal but rare that both physiological and sugar ripeness occur exactly at the same time, a decision must be made when to harvest by balancing those and other factors. Other harvest terms:

yield  the amount of fruit harvested, usually in tons/acre.

late harvest  harvesting the grapes later than normal for the purpose of concentrating sugar and flavor. Occurs around late October into November. Late harvest wines are usually finished sweet. Ice wine is made from grapes left on the vine until December or January, then picked and pressed while frozen.

leaf fall  after harvest the leaves continue photosynthesis for a time, creating carbohydrate reserves to store in the vine's roots and trunks for the following year’s growth. Eventually the leaves turn from green to their autumn color. After first frost they start to turn brown and fall.

winter dormancy  a period of inactivity due to the cold of winter, followed by a repeat of the cycle the following year.

Special thanks to Tom and Marcy Mitchell of Pa’tridge Run Farms and Fall Bright, the Winemaking Shoppe, for their help with this article. For more information or to order winemaking supplies, see their website fallbright.com, visit them at 10110 Hyatt Hill, Dundee, NY, or call 607-292-3995.   

Other sources for this article: www.nysaes.cornell.edu; plants.usda.gov; April-May 2010 WineMaker magazine.