There is one thing every tasty, deeply coloured, well-balanced and appealing wine needs – sunlight.
It is sunlight that ripens grapes, and without a minimum of 1300 heat units, this precious fruit fails to yield a flavourful wine.
On the other hand, too much sunshine scorches grapes and yields low-acid, high alcohol wine, unsuitable for a balanced wine.
One of the most important factors influencing the taste of grapes is the amount, intensity, and quality of sunlight bunches receive.
Grapes receiving optimal sunshine exposure yield better wines than those shaded by exuberant leaves. The amount of sunlight depends on site, region, and canopy management. Growers in Edna Valley, Carneros (California), Niagara Peninsula, in Ontario, Okanagan Valley, in British Columbia; Burgundy, in France, Mosel in Germany are able to expose their fruit to much more intense sunlight than others.
Areas such as Paso Robles, Napa Valley, both in California, Bordeaux, Cotes du Rhone, both in France; Rioja, Ribera del Duero, both in Spain have to be a little more careful. Too much sun can cause the fruit to get sunburned and scorched, which makes for poor fruit quality. There is a fine line that vineyard managers must walk in an attempt to grow the best possible grapes. This can be achieved by proper canopy management, of which they’re many designs, but experience is the best practical tool for establishing the most appropriate canopy design and management.
Successful vineyard managers employ the technique called “lateral removal” which demands excising shoots originating from other shoots, just above the leaf petiole (the stem that connects the leaf with the shoot). Laterals can get too large and completely shade the fruit.
Lateral removal should start right after flowering end when grapes start to develop.
The fruit must be exposed to sunshine sufficiently from the very beginning.
Veraison (the process during which the grapes begin to soften up and turn colour) occurs at different times pending prevailing temperatures. All vineyards have some level of unevenness in veraison.
Vineyard managers establish blocks to differentiate between them and harvest accordingly.
Positioning clusters on same height and exposure is practiced in Bordeaux, and single vineyards in the Sonoma County, Napa Valley, and Niagara Peninsula. This helps even ripening.
Many wineries like Robert Mondavi, Oakville in Napa Valley, and others use sorting tables. Some even use two sorting tables where each bunch is inspected twice. Rotten, scorched grapes are removed. For very expensive wines grapes are removed by hand to ensure low tannin content in the wine.
Quality vineyard fruit is always hand harvested and transported in small baskets 15 kilograms maximum).
Humans can distinguish between ripe and unripe clusters, whereas machines harvest everything at once.
Canopy and yield management are extremely important contributors to wine quality and taste.
Even the most experienced winemakers need first and foremost ripe, high quality fruit to make fine wine.