Wine Quality Factor: Harvesting Grapes
Vintners must determine the optimal time to harvest their grapes. Often the decision is influenced by the weather and the size of the crop. Once harvest approaches, a vintage is on the line and so is the winery's economic livelihood. Picking dates can make or break an entire year, directly influencing a wine's flavor and shaping its style, character and aging potential. Young, immature grapes yield wines with less depth, richness and flavor in both red and whites. The trend today among fine wine producers is to pick the grapes based on flavor rather than on statistical measurements such as sugar level or acidity. Harvesting can be either by hand or machine; the choice being decided by the type of wine to be made, financial considerations and topography.
Machine harvesting of grapes requires considerable investment, which can be a problem for smaller producers. One benefit of using a machine harvester is for speed. Machine harvesters work quickly by shaking the vine and collecting the berries which fall off, leaving the stalks behind. It is therefore, not selective, taking all the berries from the vines, whether they are healthy or ripe and is only feasible on flat or gently sloping dry land.
Manual harvesting is slower and labor intensive. It does however, allow for a great deal of selection of the grapes; unripe or rotten grapes can be left on the vine or discarded. Less damage occurs to the grapes as bunches are harvested whole; a huge benefit because oxidation begins once the grape has been punctured. Hand harvesters also use smaller containers to transfer the grapes which helps in reducing the amount of grapes damaged during harvest. In certain wine growing areas such as northern Rhône, the Mosel and the Douro, grapes can only be hand harvested because of the steep vineyards. Most high quality producers opt for hand picking. The additional costs are well worth the selective process involved when hand pickers decide which clusters to harvest and which to leave behind.