California wine is now technically as good as any in the world, but the aging capacity of California wine remains a matter of speculation. Most of the vines and the wines produced from them are too young to be properly assessed. Those wines that do have some age are difficult to come by and too expensive for the casual enthusiast.

Cabernets from California's much-heralded "classic" vintage, 1974, are now a decade old and offer some insight into the aging question. I tasted 11 of them with several hundred California wine adepts in San Francisco last fall, all of us instructed by wine expert and auctioneer Michael Broadbent. Many were surprised by the varying quality of the wines and the apparent tendency toward early maturity. I have since had a chance to taste some of these wines again, and some older cabernets, all with food and in a more leisurely setting.

The '74s featured in the California tasting were Stag's Leap Cask 23, Caymus, Inglenook Cask A-9, Mondavi Reserve, Simi Reserve, Krug Vintage Selection Lot F-1, Beaulieu Georges de la Tour Private Reserve, Freemark Abbey, Clos du Val, Sonoma Vineyards and Conn Creek. The faded fruit and general innocuousness of some of the wines were a big surprise, although others showed richness and real character, and a couple indicated a potential for greater age. The overall impression, however, was that the vintage was not as "great" as once proclaimed and that aging had produced some clear disappointments.

Broadbent's first choice was the Simi, extravagantly compared to a Mouton. His next three choices in order were the Inglenook, Conn Creek and Caymus. The popular vote put Stag's Leap first, with Simi and Conn Creek a close second and third, followed by Caymus. I picked Stag's Leap, Conn Creek and imi, with Mondavi and Beaulieu tied for fourth.

A recently sampled '74 Beaulieu Vineyards seemed much fuller and better balanced than the one I tasted in San Francisco, with hints of cherry and a long briary finish. By comparison, a '69 BV, slightly brownish in color, made a strong first impression, but the fruit quickly faded, leaving tannin and the heat of unresolved alcohol. A '70 Mondavi "unfined" cabernet had a rich, complicated nose, big varietal flavor with woody overtones and a long flavorful finish. The '72 Mondavi cabernet, however, which had been cleaned up in the wine- making process, was a much less impressive wine, balanced but lacking the character of a good old cab.

A '74 Freemark Abbey was as insipid and over-the-hill as the one encountered in San Francisco. A '68 Souverain had a nice brick color, but the fruit had not stood up to the alcohol and tannin. A '68 Mirassou was similarly gone, although the bell pepper overtones seemed capable of outlasting anything in the wine.

One of the best older vintages recently tasted was the '73 Ridge Vineyards Montebello cabernet, with good deep color and clarity, and a huge berryish nose that continued to develop in the glass. The wine was rich and still warm, with enough tannin for further age, but eminently savorous in the short term. Ridge is known for its big, well made, unadjusted wines, which may be a guide in deciding what sort of California cabernets you want to lay away.