One of the big differences between British wine writing and the American sort involves old wines. The Brits are famously fond of old wines. I recall, with a shudder, the great British wine writer Hugh Johnson enthusing in print about an ancient champagne that had a finish “like iced coffee.”

American wine writers, for their part, tend to avoid going on about old wines. Since wine appreciation is relatively new here, tales of venerable vintages leave an undemocratic, no-room-at-the-inn aftertaste of exclusion.

I have been reminded of this unspoken taboo in the past week or so, having drunk a disproportionate number of mature wines. Most of them, I might add, came from my own cellar – which is, in itself, its own unique pleasure.

These wines were not “old,” mind you. Rather, they were “mature.” The difference is all about transformation. Many wines can endure, but only truly fine wines transform, becoming something far more dimensional and resonant with age.

Some wines, such as French chablis, transform to such a degree that you would never believe, a la the caterpillar and the butterfly, that two vintages of the same chablis from the same producer and vineyard could be related, let alone identical in origin.Yet it is so.

The chance to drink mature wine is available to anyone possessed of three things: a cool space in which to store the wine properly, enough money to set aside without feeling too much of a pinch (a wine cellar is like a collection of uncashed paychecks),and sheer patience.This last element is often the most trying.

HERE’S THE (RAREST) DEAL

MAYACAMAS VINEYARDS “NAPA MOUNTAIN” ZINFANDEL 1970 This may be the rarest wine I have ever written about that you can still actually buy. The vintage date is not a typo: 1970 is indeed the vintage. Until this moment, it has never been for sale, and New York Sun readers are the first in the nation to know about it.

I have long been a fan of Mayacamas Vineyards, which is one of Napa Valley’s oldest estates. High atop Mount Veeder, the original winery began in 1889, replete with an old stone structure still in use today. It went out of business and was revived in 1941 and then purchased in 1968 by its current owners, Bob and Nonie Travers.

Mr. Travers, who is also the hands-on winemaker, is a traditionalist in the finest sense. He makes wines for the ages. Mayacamas chardonnay, for example, comes into its own only after 10 years. And it can mature for far longer than that. (The 1976 Mayacamas chardonnay is still a marvel of freshness and minerality.)

Anyway, I was visiting Mayacamas Vineyards recently and Mr. Travers casually said,”Here’s something you might be interested in tasting.” He likes to serve visiting wine writers so-called off-vintages, the better to demonstrate that what might be true for Napa Valley in general isn’t necessarily so for Mayacamas Vineyards, 2,000 feet above the valley floor.

Out comes a bottle of 1970 zinfandel with the antique designation “Napa Mountain,” a term no longer in use. (Thirty-five years ago you could pretty much say what you liked on a California wine label.)

Now, zinfandel is not known for transformation. It tends to be best while its intense fruit is still fresh and vibrant. A 35-year old zinfandel that’s really worth drinking is not merely improbable; it borders on the preposterous. Mr. Travers said nothing.

The wine was poured and the color was awfully fresh, a bright (if slightly cloudy) garnet with no signs of the orange or brown tints that signal aging. On color alone you’d say, oh, 10 years old.

But it was the scent and taste that astonished. This 1970 zinfandel was plumped – that’s the only word – with vibrant, surprisingly fresh-tasting fruits such as wild cherry, strawberry, and black cherry. What’s more, it was laced with zinfandel’s signature spiciness, which is often the varietal feature that diminishes first as a zinfandel ages.

The experience grew more profound as we finished the bottle. The depth and density of the wine increased upon prolonged exposure to air. (Old wines, like fading opera singers, often deliver an aria of fragrant, delicate scent and then suddenly collapse, exhausted of fruit.) Finally we reached the blackish sediment. It, too, was “sweet” and flavorful.

I demanded to know the story on this wine. Mr. Travers obliged with a satisfied smile. “This zinfandel came entirely from a 1-acre plot of 100-year-old zinfandel vines on the old Jerry Draper vineyard on Spring Mountain,” he said. “Those vines were huge monsters with massive trunks and tiny berries. I was only able to buy the grapes that one year, though. The vines were later ripped out.

“I made the wine here at Mayacamas. There wasn’t much, a total of 35 cases. Our old stone cellar is very cold. And for whatever reason – winter cold, low pH – this wine just wouldn’t go through malolactic fermentation. So the hard malic acid never transformed into softer lactic acid. As a result, the wine was hugely tart. It was never fined and only coarsely filtered.We put it in bottle and forgot all about it.”

Only now, Mr.Travers said,has his 1970 zinfandel become “drinkable.”That is an understatement.It is superb red wine:smooth,intense,astonishingly fresh, and perhaps the most characterful zinfandel I have ever tasted.”We’re keeping some for ourselves,” he said.”After all, we did wait 35 years to drink it.”

Mayacamas Vineyards is now releasing this “lost” 1970 zinfandel for the first time. Available only from the winery (707-224-4030), the price is $100 a bottle, with a maximum sale of six bottles a person.

While $100 a bottle is hardly chump change, keep in mind that several California zinfandels now routinely ask $40 to $75 a bottle for the latest vintage – without throwing in 35 years of aging in a cold stone cellar. This is a great wine that obviously won’t come our way again. Get it while you can.