In early spring, when the soil has warmed to at least 50 degrees, sap begins leaking from pruned branches, and tiny buds emerge on the vine.
In May or June, shoots that have sprung from the buds form flower clusters—small green blooms—that make way for pollination (most vines are hermaphroditic).
Almost immediately after flowering, the fertilized bloom forms a seed around which the berry grows. The grape skin and tannins begin to mature.
Still sour, green, and hard, the grapes start to ripen in August. The fruit changes color, softening as sugars build up and acidity decreases, then doubles in size.
The fruit is picked between September and October, depending on the varietal as well as on the acid and sugar levels. It’s crush time. The winemaking begins.