Grape ripening

Grape ripening is the process in which grapes develop from sour, green berries into ripe fruit that is ready for harvest. During ripening, which begins at the stage known as véraison, the grapes accumulate sugar and aromatic compounds while the acidity falls. It is this balance between sugar and acidity that determines whether a tasty wine can be made. Underripe grapes give thin wines with sharp, high acidity, while overripe grapes give wines with low acidity and a flat, heavy character.

Ripening means a great deal for what you experience in the glass. In the skins of red grapes, colour compounds and aromatic compounds build up, and this is where a large part of the wine's aroma and depth comes from. In white grapes it is often about capturing the fruit's fresh aromas while a suitable acidity is still present. That is why white grapes are typically harvested a little earlier to preserve the acidity, and red grapes a little later to gain more colour, ripe tannins and lower acidity.

A good way to understand grape ripening is to think of unripe fruit from the garden: bitingly sour and green, where the ripe version is sweet, fragrant and round. The grower tastes and measures the grapes continuously to hit the right moment for harvest, because ripening can vary from spot to spot in the vineyard depending on the sun and location.