A general calendar for the stages of the vine during the production of grapes.
Budbreak - Day 1: Winter pruning has already commenced (see below). Budbreak occurs at 50 degrees (10 Celsius). Buds look like popcorn before they burst open. The vine rapidly pushes out its first leaves and clusters.
Bloom - Day 60: The vine flowers. It is crucial that weather is good during these 2 weeks. Adverse weather can result in Coulure or “shatter” meaning some of the grapes fail to develop. Another problem is millerandage where there are grapes of different sizes and levels of maturity within the same bunch. Successful pollination leads to berry set. During this time we also disc and till under the cover crop.
Veraison – Day 100: Until now, the grapes have been small, hard and the color of green apples. Two things happen during veraison: on the outside, the grapes soften and become purple (or yellowish-green on white varietals). More importantly, sugars and phenols (flavors) start to build inside the grape, while malic acid is lost. This continues to accumulate inside the grape until…
Harvest – Day 160: After sufficient maturation, the grapes are ready to be picked. The color should all be uniform and should taste sweet. The seeds turn brown and you can crunch right through them in your mouth. Grapes for sparkling wine are typically picked first, followed by whites, reds then late harvest/dessert wines.
Leaf Fall – At first frost
*These numbers might not fit every region, but it takes 140 to 160 days from bud break to harvest. This could range from 125 to 200 days in extremes.