Viticulture - Green Harvest

A green harvest is the removal of immature grape bunches, typically for the purpose of decreasing yield. In French, it is known as a vendange verte.

Green harvesting is a relatively modern practice most often used to produce fine wine. Removing the tiny, immature grapes while they are still green induces the vine to put all its energy into developing the remaining grapes. In theory this results in better ripening and the development of more numerous and mature flavour compounds. In the absence of a green harvest, a healthy, vigorous vine can produce dilute, unripe grapes.

Many traditionally renowned regions have natural conditions that suppress excess vigor. Examples include the gravelly soil of Bordeaux, the often cool climate of Burgundy, and the meager rainfall of Rioja. In these regions, the vine is prevented from producing too many grapes without human intervention. However, in regions with fertile soil, copious sunlight, and irrigation, the vine can generate huge quantities of characterless grapes. One solution is a green harvest. After fruit set, the quantity of grapes that will result from a vineyard can be estimated. Often the grower has a target yield in mind, measured in tons per acre or hectoliters per hectare. A portion of the grape bunches are cut off, to leave approximately the correct amount.

In Europe, many appellations restrict the yield permitted from a given area, so there is even more incentive to perform green harvesting when presented with excess crop. Often the excess must be sold for a pittance and used for industrial alcohol production rather than wine.

While the concept of thinning or sacrificing part of the grape crop, i.e. green harvesting, with the aim of improving the quality of the remaining grapes, predates modern critics, the practice has increased in recent times in vineyards found in California and areas where the grapes grow easily. (McCoy)