SONOMA, Calif. – One of the longest-running smears in wine is that California wines don’t age well. Just why this assertion, which is put forth as fervently as any JFK assassination theory, should persist is worthy of a little college thesis.

Partly it has to do with the fact that until recently, most non-Californians hadn’t tasted much beyond the California jug. Call it a baseline error.

But it also has to do with the curled-lip descriptor “domestic,” perfectly captured by H.G. Wells in his famous observation: “You Americans have the loveliest wines in the world, you know, but you don’t realize it. You call them ‘domestic,’ and that’s enough to start trouble anywhere.”

But mostly the idea that California wines don’t age is due to a simple lack of longevity. For example, decades ago, when I first started writing about wine, I put together a tasting of every vintage-dated Napa Valley cabernet sauvignon from the much-lauded 1966 vintage. There were fewer than a dozen. Today you’ll find hundreds.

So when it comes to assessing – or recognizing – the longevity of California wine, most wine drinkers haven’t had much to go on. Numerous tastings since the 1980s, however, have repeatedly shown that California wines, especially cabernets, age beautifully. Yet particulates of doubt still hang in the air, creating a kind of snob smog.

If you want to lay to rest any doubt about California wine’s ability to both endure and, more importantly, transform, then you only need visit Hanzell Vineyards on the slopes of the Mayacamas Mountains just outside the town of Sonoma.

Founded in 1953 by James D. Zellerbach (of the Crown Zellerbach paper and pulp company), Hanzell was the first post-Prohibition winery consecrated to refinement.

Zellerbach was a Burgundy lover. Enraptured by Burgundy’s pinot noirs and chardonnays, he decided that his native California should pursue the same sort of beauty. So in 1948 he bought 200 acres of hillside property near the then-sleepy town of Sonoma and planted pinot noir and chardonnay.

Doesn’t sound like much, does it? Consider this: At the time Zellerbach planted chardonnay at Hanzell, there were fewer than 100 acres of chardonnay in all of California, according to Frank Schoonmaker and Tom Marvel in their landmark 1941 book “American Wines.” (Little changed for decades. As late as 1964, chardonnay occupied just 600 acres. Today, California has 96,000 acres of chardonnay.)

After a daunting start in 1952 (the first vines had to be replanted after a harsh winter eroded the soil), Hanzell got going in 1957. This was a significant date in California wine history, because it was at Hanzell, in 1957, that California saw its first stainless steel fermenting vats, personally designed by Zellerbach himself.

Each vat holds exactly a ton of grapes and has a hollow “jacket” to allow fermenting temperatures to be controlled by filling the hollow jacket with hot or cold water. At the time it was revolutionary. Today, it’s universal. (The vats are still there and occasionally used.)

Hanzell’s other contribution was also a California first: small French oak barrels for aging wine. Unlike the revolutionary temperature-controlled stainless steel vats, this was common-sense traditionalism for Zellerbach. He figured that if he wanted to make chardonnay and pinot noir that tasted like Burgundy, then he should use the same barrels as the Burgundians. So he had some shipped over.

But in 1957 using French oak barrels was not merely novel, it was almost unknown. Peter Mondavi at Charles Krug Winery in Napa Valley had bought a few French barrels around the same time. But that was strictly experimental. Hanzell, in comparison, was resolute in its conviction: It was the sole winery in California to use only French oak barrels for all its wines. That was something unseen elsewhere in the state until well into the 1970s.

All this significant history aside, it still comes down to grapes. This is where Hanzell shines, nowhere more so than with its chardonnay. For decades, Hanzell chardonnay has demonstrated, vintage after vintage, decade after decade, that it can age as well as any white Burgundy. What’s more, it does not merely endure, but transforms. That is the hallmark of great wines anywhere.

Anyone skeptical that California wines are able to age well can do no better than place their (grudging) trust in Hanzell. It has a track record like almost no other winery in California. This was brought home to me again, not for the first time, at a recent tasting in Hanzell’s original, Zellerbach-designed winery, a small, woodsy affair loosely modeled on the chateau in Burgundy’s Clos de Vougeot vineyard. (Now there are also new underground tunnels where the wines are made.)

Eight wines were served over the course of a simple lunch, equally divided between Hanzell’s distinctively earthy, long-lived pinot noir (more about that in a moment) and its more famous chardonnay.

Absent, however, was Hanzell’s cabernet sauvignon, which had a brief (by Hanzell standards) run from 1981 to 1992. Although a remarkable cabernet sauvignon – one of California’s most distinctive, in this taster’s opinion – it failed to win sufficient admiration and the vines were grafted over to chardonnay and pinot noir in 1993.The few bottles I have remaining in my cellar are among my most prized wines.

As for the Hanzell pinot noir, I remain torn. I enjoy its earthy, site-inflected flavors while remaining aware that it’s not quite a benchmark pinot noir. It fails to deliver a full measure of that variety’s signature berryishness. It’s a one-off, like looking at a painting by a renowned master that is indisputably authentic but not quite among the master’s defining classics.

About the Hanzell chardonnay, I have no such qualms. It is a masterpiece. Hanzell chardonnay is consistently one of California’s greatest, bar none. And unlike many other California chardonnays, it long ago proved it can go the distance.

Four chardonnays were served: the not-yet-released 2003, which shows the fruit intensity of that unusually hot vintage; the stellar 2002 (see below); a captivating, utterly thrilling 1994 that is only now “just so” in its mature perfection; and an aging but far from antique 1975 chardonnay with a whiff of the caramel of older chardonnay but offering impressive vitality and an exceptionally long aftertaste.

HERE’ S THE DEAL

HANZELL VINEYARDS CHARDONNAY 2002 Of the many Hanzell chardonnays I’ve been privileged to taste, I cannot recall a better young Hanzell chardonnay than the 2002 bottling. It is, without question, one of the very best young chardonnays Hanzell has offered in the past few decades.

This is Hanzell chardonnay at its most classic and compelling: crisp, filled with minerality so often lacking in California chards, and already delivering a long, palate-staining finish. Not least, it displays impeccable equilibrium, a high-wire act of dense, intense fruit balanced by bracing acidity. In a word, it’s superb. This is not merely great California chardonnay – it’s great chardonnay, period.

Although more than drinkable now, experience reveals that the 2002 Hanzell chardonnay will surely do nothing but improve for at least another decade if stored in a cool space. So if your patience and pocketbook allow, you are well advised to buy enough to stow a few bottles away for a more profound (wine) future to come. $55.