No, this isn’t what happens the day after a party when your head hurts and you painfully recall all the drinks you had during (and after) dinner.

Budburst, or débourrage, is the time of year when vegetative and floral buds develop to make way for their budding (the down of young leaves and flowers buried in the bud) and then their leaves and flowers. Okay, but in concrete terms, what does budburst mean for a vine?

When we look at the life cycle of a vine, we see that it is subdivided into two stages. First, the winter cycle, from November to February, during which the vines rest. Then comes the vegetative cycle, from March to October, during which the vine grows, develops its foliage and produces its fruit, the grape. Budburst marks the beginning of the vegetative cycle and is its first stage. It’s the moment when the buds on the vines open up, revealing their buds, the little fuzz that will later become the vine leaf.

For budburst to take place, it is absolutely essential that the temperature is stable and not too low for a sufficient period, and that a sufficient level of daily light allows sufficient potential for photosynthesis. When these conditions are met, the vines wake up, soak up water again and start circulating the sap that will later cause the buds to open.

The reason we’re so interested in this phase of the vine’s life cycle is that it has an impact on the grapes that will be harvested in the autumn. If bud break is long, the different buds don’t open at the same time, so the grapes ripen at different times. On the contrary, a short budburst will synchronize grape ripening, resulting in an optimal harvest.

NB: during the bud-break phase, the bud is much less protected from the cold (-2° maximum vs. -15°/-20° inside the bud). During late spring frosts, the layer of ice surrounding the now exposed bud acts like a magnifying glass when exposed to the sun: the bud is burnt and the annual harvest is compromised.