Harvesting Grape
If all goes well grape is being harvested manually or mechanically when it is ripened. The time and type of picking grapes are commonly chosen by winemaker. The decision is usually made according to sugar, acid and pH levels of the grapes but a winemaker often also takes into account taste, flavor and color of the fruits, overall condition of the grapevine, seasonal variations and future weather forecast. Bad weather conditions such as heat, storms, hail or frost can severely damage the grapes.
Harvest season, in Europe known as vintage and in America as the crush, takes place from August to October in Northern Hemisphere and between February and April in Southern Hemisphere depending on weather conditions, grape varieties and wine styles. Grapes for making ice wine is picked after frost usually in January (in Northern Hemisphere).
Besides the right time for harvest very important decision that each winemaker has
to make is whether to pick the grapes manually or mechanically. One of the greatest
advantages of mechanical harvest is lovering the costs and saving time because
mechanical harvesters can cover large area in relatively short time and require very
little manpower in contrary to picking grapes by hand. However, mechanical
harvesters do not select between healthy and moldy bunches and often also harvest
non-grape material especially leaves and steams and sometimes even peaces of metal,
stones and small animals. For that reason many winemakers still prefer hand-picking
although it requires more time and more manpower. Besides that some types of wine
require separation of individual berries from botrytized bunches what can be done
only by hand.