Hang Time studies
Brix levels at harvest for Cabernet Sauvignon have been steadily increasing in recent years as winemakers strive to improve wine quality by waiting for green fruit characters to go away.
Napa County Hang Time Study
A Napa Valley hang time study investigated the effects of extended ripening periods, or "hang time", on Cabernet Sauvignon.
Whereas sugar accumulation appears to stop once the berries reach 25-26º Brix, other physiological changes continue to occur that may affect wine quality.
There was considerable variation in the response to extended hang time among the vineyards studied in this trial. Nevertheless, these data indicate that a 5% reduction in cluster weight per degree Brix is a reasonable estimate of what might occur in Napa Valley Cabernet Sauvignon vineyards with extended hang time.