They show not only how the wines develop with bottle age, but also the evolution of winemaking style, and even of the vineyard as the vines age.
Carrick, in Central Otago, held a vertical tasting recently of 10 years of riesling and pinot noir grown in its vineyard in Cairnmuir Rd, Bannockburn.
The rieslings reflected the story of the variety in Central.
In the 1990s, winemakers tended to overcrop it, but for the past 10 years they have been taking it more seriously.
The older wines (2001, 2002, 2003) were bigger and richer, with hints of lime, lemon and mineral and even developing buttered toast characters.
From about 2006, with a change in winemaking style suggested by board chairman John Comerford, and new winemaker Jane Docherty from 2008, the wines were lower in alcohol, with more finesse and delicacy, and hints of stonefruit rather than lime and citrus.
It certainly demonstrated that well-made Central Otago riesling will develop for a decade at least - even the oldest were lively and delicious, showing how long-lived the variety can be.
Not quite so with the older pinot noirs.
The two earliest, 2000 and 2001, were tired, fading into hints of Marmite, but still showing the firm tannins characteristic of the Carrick vineyard.
Vintage variation was obvious among the pinots - the big, rich 2002, the charming, classy 2003, the savoury 2005, the charming, textural 2006, and the sneak preview of the deliciously silky 2009.
In 2008, a year they did not consider good enough to make Carrick Pinot Noir, they produced Crown and Cross, a cheaper label that, however, is full of charm and easy to drink.
A vertical tasting like this allows the vineyard characteristics to emerge.
Length, texture, and a firm tannin structure seem typical, with cherries and dark berries in the young pinots developing into savoury layers with a few years' bottle age.
Carrick was also launching the Excelsior 2007, the third release of its super-premium pinot noir.
Janet Lyall, chef at Carrick's restaurant, had carefully matched each of the three vintages, as well as chardonnay and pinot gris, with different courses.
The Excelsior 2007 is a big, young wine, almost syrah-like, but floral, silky and complex, with huge potential for cellaring.
It went well with slowly braised beef cheek.
The earlier vintages, 2005 and 2006, are still developing - perfumed, complex and superbly long.
Give them another four or five years at least if you are lucky enough to have some in your cellar.
Clarification
Last Wednesday I mentioned two new wine labels from the "defunct McArthur Ridge development", parts of which are up for mortgagee sale.
Fraser Skinner of Harcourts Real Estate in Arrowtown, which is handling the sale, says his client is upset over the term "defunct", as the large pinot noir vineyard portion of the development is being maintained and he understands the grapes are being sold.
Details can be found on www.mcarthurvineyard.co.nz
