Definition - What does Cluster Thinning mean?
Cluster thinning is a viticulture technique used to remove flower or fruiting clusters on the vine. This process helps the viticulturist equalize or adjust the vine balance. This technique should be used with care as it is dependent on the climate, vine strength, vine vigor and overall health. Some vineyards need thinning on an annual basis and must have the schedule perfectly timed as well as the quantity thinned.
WineFrog explains Cluster Thinning
Cluster thinning can be a delicate science as it depends on timing, how much thinning is needed, climate and vine characteristics. In cool climate vineyards, crop thinning is used to optimize ripening because the heat is low, limiting the ripening time and there is a reduced growing season. The timing is important because depending on the time the crop is removed the other clusters will grow faster to compensate. The amount of crop thinning can change each season and it needs to change as climates and growth change every year. The goal with crop thinning is to help certain varietals achieve a higher quality and yields but some critics think that crop thinning can actually do more harm than good. Some viticulturists even believe that crop thinning had little effect on actual yield and only important for the commercial business aspect of wine making.