The term " vieille vigne" ("old vine" ) used on some wine labels is supposed to indicate that the wine has been made from vines considered to be old. However, this term is not governed by any specific legislation, and can therefore cover different winegrowing realities. What's more, older vines are generally considered to produce better wine, but this too is not always true.
"Old vines"... a relative age
As there is no legal framework for this term, it simply means that the wine bearing it is made from the oldest vines on the estate. It is considered that vines under 20 or 25 years of age cannot (should not) be qualified as "old", as it is at this age that they become "adult". However, depending on the conditions of planting, production, soil, quality of plant material and grape variety, this marvellous plant can happily reach several centuries of existence! The oldest vine, for example, can be found in Maribor, Slovenia, where it was planted 400 years ago. There are also vines dating back to the 19th century in France. This means that the term "old vines" can just as easily refer to young 25-year-old vines as to old vines over 100 years old. This relative age depends on the average age of the estate's vines. The best thing to do is to ask the age of the vines used to make the wine.
Do older vines make better wine?
Legally, you can make wine from 3-year-old vines. Quality wines made from vines less than 10 years old are generally light and full of freshness. Between 10 and 20 years of age, the vine is more spirited, and its vigor needs to be controlled to avoid producing wines without personality. When they reach 20 or 25 years of age, yields stabilize and tend to decrease. If the soil (absence of hard rock) and production conditions (quality of plant material, sparing use of fertilizers) allow, the roots will go deeper. Deep-rooted vines with controlled yields are said to produce richer, more concentrated, sapier wines that better express the characteristics of their terroir.