California wines are making a splash in Britain: merchants are specializing in them, restaurants are listing them and respected connoisseurs are producing a stream of articles appraising them.

The Californians' entry has been aided by their high quality, as well as by the escalating price of old French classics, and by the strength of the pound against the dollar.

"It had to happen sometime," Hugh Johnson, one of Britain's most respected wine writers, said recently."British drinkers are fed up with French price increases and want to try new wines. The California wines are good, and the French will be forced to match their prices."

Britain's biggest specialist importer of California wines, Londoner Geoffrey Roberts, who offers 60 top California labels, says his trade has doubled in the last year with 20,000 cases sold in the last three years.

"I am here to stay," he said recently. "I intend to see the time when great California wines of Mondavi, Heitz and Chalone are as well known as Lafite and Montrachet."

That day may come, but the Californians will have to fight a little longer.

Britain virtually invented wine connoisseurship, with centuries spent developing great wines such as Bordeaux, port, sherry and Madeira and a tradition of critically buying the best from around the world.

At the first auction of American wines ever in Europe, Sotheby's in London offered 60 different California wines at the end of June and held a public tasting beforehand.Tasters were impressed by the wines' quality, but surprised that they were not cheap -- a common misapprehension among Europeans about quality California wines.

At the auction itself, the less known wines did not make top prices or did not sell at all. But big-name wines and wines of obvious outstanding merit did bring top prices, with a case of 1972 Heitz Martha's Vineyard cabernet going for $407 and a Chateau St. Jean 1978 dessert riesling selling for $25 a half bottle.

One would-be British buyer, John Symon, pronounced the Chateau St. Jean "Absolute nectar. Peaches and apricots." Several tasters compared the wine favorably with the greatest dessert wines of Germany.

Still, British experts caution against comparing the California wines too closely with European classics.

The doyen of British wine writers, Harry Waugh, who frequently visits California and knows the wines well, said recently: "In their own right California wines are first rate and should be assessed on their own merits. A California cabernet can be a knockout, but you get more finesses from Bordeaux. Both are good, but they are different."

The most frequent criticism here of California wines is that they are too rich and lack subtlety.

While that may be, as long as the wines remain cheaper than top French rivals now selling for between $10 and $30 a bottle, they should find a place in the British market. Neville Abraham, manager of one of Loundon's best wine shops, Les Amis du Vin, now offering a wide range of California wines, said recently: "The potential for them is good, but it will take time. The best California rank with the best French, and the average is much better. They will make their mark."

Wine trade sources say they expect the big U.S. wine companies to fight for the lower price British table wine market in the new few years and rate the chances of success highly.

A dining society called the Zinfandel Club devoted solely to appreciating California wines thrives in London. And with the wines featured on the capital's best wine list at the Tate Gallery restaurant, the American upstarts are off to a good start.

Assessing their British future, Waugh said: "The California growers have money, research and enthusiasm. I wouldn't put anything past them."