I like to launch some notes about this controversial aspect as many producers and enologists say that best wine are produced from oldest plots!
But.. how old? Unfortunately, there’s not a regulated definition of “old vine” and commercial reality dictates that vines should be regularly replaced also because older vines need more work for less yield.
The only thing we can do is observing the practice of each country, each culture.
Even in in Australia there are vines that are 100 years old that are still in production; yet, life expectancy of vineyards in South Africa is 20 to 25 years before they become not economically viable; In the central Loire, most producers who use the term vieilles vignes do it with a minimum of 30 or 40 years old. Producers from Chile agree: 30-40 years is a minimum.
What do you thing about it?
Source: the drink business