How wine grapes are grown and harvested

A picked grape never gets any sweeter, so a vineyard cannot fix a bad harvest date later.

stations: 5
things downstream: 12

The short version

A grapevine runs on a yearly cycle. Growers prune it while it rests, then watch buds break in spring, flowers set into berries, and fruit soften and change color at véraison. Many vineyards net the crop against birds. Picking, by hand or machine, is timed to sugar, acid and pH, because sweetening stops the moment a cluster leaves the vine.

Prune the dormant vines

In late winter or early spring, once the worst cold has passed, growers cut back last season's wood. How much they take off sets both the leaf growth and the size of the crop for the coming year.
Wait out budbreak and bloom

Buds swell in early spring and show their first green leaves. Several weeks later shoots can add an inch or more a day, flowers open, and tiny green berries set. Fruit set is when growers can first gauge the size of the year's crop.
Manage canopy and crop load

Through the summer the viticulturist handles pests, fertilizer, irrigation and the leaf canopy. Some growers also cut away immature bunches in a green harvest, so the vine puts its energy into the clusters that stay.
Net the fruit at véraison

Berries soften. Dark varieties move from green to red, purple or black, while white ones turn translucent, and sugar starts to build. Around now many vineyards hang netting to keep birds off the fruit.
Pick by hand or machine

Readiness is judged on acidity, pH and sugar, and sometimes on the weather and when a crew can come. Clusters come off by hand or machine, then get processed on site, carried to a winery buying the fruit, or moved into cold storage.

End of the lineWine grapes Next it goes into vinegar, wine, champagne and 3 more.

Worth repeating

The oldest known winery, in the Areni-1 cave in Armenia, dates to about 4100 BC.
In its fastest stretch of growth, a grapevine shoot can gain an inch or more in a day.
A healthy, vigorous vine left with all its bunches can give dilute, unripe grapes.