Old vine (French: vieilles vignes, German: alte Reben), a common description on wine labels, indicates that a wine is the product of grape vines that are notably old. There is a general belief that older vines, when properly handled, will give a better wine. There is no legal or generally agreed definition for old.
Grape vines can grow for over 120 years. After about 20 years vines start to produce smaller crops, and average yields decrease, leading to more concentrated, intense wines. Diseases such as "dead arm" can also afflict old vines, in some cases further concentrating the juice. "Old vines" might apply to an entire estate, or it might mean only a certain parcel planted before others. In the U.S., the most common use is on Zinfandel, because in California vineyards up to 125 years old are still bearing small amounts of prized Zinfandel fruit.
In a place where wine production is longstanding, it often means a wine whose vines are thirty to forty years old. Some wine makers insist the vines should be older than this. In newly established wine regions, twenty years might be old. The definition is further complicated by the fact that certain varieties simply do not have economically viable yields when they get truly ancient.