Old vines means exactly what it says, the vines are old. If a portion of a vineyard has old vines, meaning the vines could be upward of 125 years old, the vines yeild much lower crops than young vines but produce much more concentrated and intense wines. The term has no legal meaning in the wine world like "VQA" because a winery could call vines which are 20 years old "Old Vines." If you see the term on a bottle from a reputable winery then it is probably more likely that the wine is actually from very old vines.
A disease called dead arm can afflict old vines in some cases making the wine even more concentrated and intense. This disease is caused by a deep rooted wood rot in the arms of the vines. Over the years the arms of the vines will die individually until eventually the entire vine dies.
A disease called dead arm can afflict old vines in some cases making the wine even more concentrated and intense. This disease is caused by a deep rooted wood rot in the arms of the vines. Over the years the arms of the vines will die individually until eventually the entire vine dies.
So I guess the old adage is true, but in reverse.
Wine is like women, it gets better with age.