🍷 Photosynthesis

Photosynthesis is the work of leaves in which sunlight, water and carbon dioxide from the air are turned into sugar. As a by-product the plant releases oxygen. It takes place in the green cells of leaves thanks to chlorophyll, the pigment that catches light.

For grapes, photosynthesis is the basis of everything. The sugar the leaves make by day is sent by the vine into the bunches. The berries store it through the summer. Later, in fermentation, yeast turns this sugar into alcohol. So the better the leaves work, the more sweetness in the grapes and the stronger the wine can be.

Growers try to have enough leaves but no needless shade. The vine's canopy is shaped so that light reaches both the leaves and the bunches. Foliage that is too dense keeps berries from ripening, and foliage that is too sparse gives little sugar. The health of the leaf matters too: disease and pests reduce photosynthesis.

So the leaf canopy, the grape leaf and the sugar of grapes are linked.