There are many different varieties of grapes – everything from table grapes to grapes to make wine. When it comes to deciding when to harvest grapes, there are three main groups: early, late and medium-ripening. Consequently, harvest times depend on how ripe the grape needs to be.
What is Ripening?
The ripening of grape vines occurs when the grapes begin to turn color, but this is not the time to pick them! Wineries prefer more scientific ways to decide when to harvest grapes. These including exact sugar contents and pH levels (brix). Wineries can use different methods like pruning, picking and tying to determine when to harvest grapes.
Once the ripening process has been completed, grapes are harvested at this point for two reasons. First, grapes ripen at various rates, depending on the amount of sugar. The slower the ripening of a grape, the longer the grapevine must be exposed to sunlight, which helps to speed up the process. Second, harvesting grapes is beneficial to the wine making process because the extra sugars within the grape are converted to alcohol, which adds flavor to the wine and makes it alcoholic.
What Happens Next?
After the ripened grape is harvested, it can either be stored immediately or must be rinsed to remove the excess juice and other solids. After rinsing, the grape air dries for a few days before being stored. Grape should never be stored without racking or pinning because there is a risk of rotting.
Furtuermore, the more grapes harvested during the year, the higher the possibility that the wine will have sediment in it. The more sediment, the less fruity and flavorful the wine will be. Racking the wine ensures that all the solids and juices are removed from the wine so that the wine will retain its original flavor and taste.
Another method used for harvesting grapes is the use of hand-picking or hand-ripping. This involves removing the majority of the leaves and fruit off the vines, which are then transferred to a storage container. The most important thing to note about hand picking or hand-ripping is to only do this when the grape is fully ripened.
Harvesting grapes also varies depending on the variety of grapes harvested. Some grapes require a lower ripening rate, while others may need more sugar than others. The quality of wine is also affected by the ripening rate. The longer the ripening period, the more fruit and leaves the grapes should be exposed to sunlight and more nutrients. The best time of year to harvest grapes depends on the ripening process. In the Willamette Valley, we typically harvest our grapes at the end of September/early October.