The growth calms down at flowering. In warmer parts of the Languedoc, Chardonnay vines are already showing 50 cm of shoot growth, indicating about 3 weeks advance on Chablis and the cooler parts of the Languedoc. About 6 to 13 weeks after budbreak, when the average daily temperature reaches 15 to 20 C, the vines flower. Grape flowers are nothing spectacular, being small and green. Vines tend to self pollinate and as soon as flowering occurs, successful pollination leads to fertilization and the formation of berries with seeds in them.
Larger berries have more seeds, up to a maximum of four.
In reality only about 30 percent of all flowers become berries. The latter is referred to as coulure and if the number of berries that fall off is relatively limited, it can be appreciated, as it reduces the number of grapes to ripen, therefore concentrating flavors and reducing the yield. However if coulure causes large numbers of berries to fall off, the yield can be drastically reduced, greatly affecting the grower s crop. Another possible problem during fruit set is millerandage or when fertilization does not occur properly and some berries don t develop seeds. The problem can be identified by small and large berries found on the same bunch of grapes.