The Grapevine Vegetative Cycle Part III

The Grapevine Vegetative Cycle Part III

Over the past few months, we have been following the development of the grapevine. March is truly the beginning of the growing cycle, following the pruning.

A Recap of the Vegetative Cycle:

Bleeding of the vines between February and March
• Bud break in April, dependent upon temperature
• Flowering starts in May, 40-80 days after bud break
• Fruit set almost immediately follows
• Veraison (the onset of ripening) takes place around 40–50 days after fruit set
• Maturation and harvest

 

Veraison
This is a French word (“verr-ray-zohn”) which identifies a precise time in the vegetative cycle when vines are creating color for their grapes. Water and acids are making their way to the end result of photosynthesis: sugar. The grapes turn from green to light yellow, gold or red and naturally begin to sweeten. This process starts in late July in the Northern Hemisphere and in late January in the Southern Hemisphere.

 

The Grapevine Vegetative Cycle Part III - veraison of grapes

 

The main compounds responsible for grape color are called anthocyanin or polyphenols. The berry is preparing the seed for maturity by growing in size to ensure its protection from the elements. Just before veraison, a green harvest can sometimes be performed. The goal of a green harvest is to reduce the number of bunches, so the remaining bunches can get more energy, sugar and color. Those bunches will yield an overall higher quality to the consumer.

From this point on, depending on your geographical location and the varietal produced, full maturity will be completed between 35 and 80 days.

 

Maturation
Some grape varieties have bunches that ripen very unevenly. Uneven ripening is a characteristic that can be found in Pinot Noir, Sangiovese, Malbec, Gewürztraminer and Zinfandel. These varietals are more challenging to grow no matter what the climate is.

Over the summer, the entire plant is maturing, from the wood turning brown, growing in length and size, to the berries hardening and increasing their sugar content.

Harvest takes place over several months. For sparkling wines, more acid and less sugar is desirable, so grapes can be picked as early as the end of July but mainly in August. All varietals ripen at different times and from August to November, wineries fill up their tanks. In the Southern Hemisphere, harvest time is in full swing in February and March. In some cases, as in the making of ice-wine, harvest goes well beyond fall into wintertime.

 

The Grapevine Vegetative Cycle Part III - vines and purple grapes maturing on the vine and about to be harvested

 

Harvest time is a crucial moment when the grapes reach their perfect ripeness. Viticulturists and winemakers work around the clock to pick the grapes. Their spouses are called “Crush Widows” because they do not see them for weeks during this important time in the grapevine’s vegetative cycle.