Ever since way back when I'd known that Switzerland takes a lot of beating as a mecca for tourists - whether the requirement is a fabulous choice of ski runs in winter, fresh cool air and glorious landscapes in summer and fall, or the solid comfort of attractive, well run hotels the year round. However, when confronted by a distinguished oenologist who allowed that his country also "made the best range of dry white wines in the world," my look of disbelief was almost audible.

"First of all," he said, "when you buy a Swiss wine you can be sure it is made from healthy grapes, by expert workmen, in a spotlessly clean winery. What is in the bottle is exactly what is specified on the label. Secondly, "Since 95 percent of our white wines have no residual sugar, a major effort is concentrated on the difficult process of producing stable, dry, white wines."

The "best range" contention was still difficult to accept. About 80 percent of Swiss whites are made from one grape - the Chasselas. There is an impressive variation in character of Chasselas wine, however, depending on difference in vineyard location and exposure.

Petillance in Swiss wines is a carefully cultivated characteristic. It is a principal reason for the "freshness" that people note in describing their charm. Because the Swiss climate makes clarification of wine relatively easy, fermentation can be completely finished and the wine absolutely clear, yet with tiny residual bubbles of CO2, when bottled.

Some critics note that Swiss wines are low in alcohol. But for many of us this is probably a blessing in disguise. The difference between about 9 1/2 to 10 1/2 percent and 11 1/2 percent certainly shouldn't cost consumers any pleasure. But it does allow producers to dry their wines right out and then stabilize them, with about a third the amount of sulphur used elsewhere. Because of this, even enthusiastic consumption leaves you without a thick head or a thirst next day.

An important factor in the high quality of Swiss wines is an Association of Chef-Cavists. Founded about 50 years ago in Zurich, the association soon decided to have oenologists, merchants, and other connoisseurs join with members in an annual degustation. The event is in no sense a competition. The objective is a gathering to taste and discuss new wines: a forum where "producers can hear what other experts have to say about their wines and learn how to improve them."

Each year 125 to 150 samples of wine are submitted to the association for independent assessment. Of these, a selection is made, representing all wine regions in the country. It was 112 in 1968, but has come down to a more manageable 80 to 85 of late. While this number is peanuts compared to many European tastings, all tasters invited are expected to taste all wines; a tour de force that lasts the whole day.

The selected wines are first tasted by a few experts, who reach a concensus of the notable qualities and technical features of each of them. At the main tasting, 125 or so participants are offered three wines at a time, and given a few moments to form individual opinions. After this, the report of the experts is read, and participants are invited to comment from the floor.

Four times with the Chef-Cavists, and extensive tasting through the years, have pretty well convinced me that the "best range in the world" claim probably wasn't as chauvinistic as first thought. Alsatian friends would probably question this change of heart, as would some Californians - and certainly many Germans.

In respect of the latter, however, I recall visiting an important winery in the Rhinegau and at the end of technical discussions, asked what wines I would like to taste. I specified only one - a dry wine. Clearly this posed a problem. Eventually my hosts were able to produce a dry wine which, without exaggeration, was a complete nothing!

Though seemingly incredible when you consider the latitude of Switzerland, 19 of 22 cantons produce wine. The Valley of the Rhone (three cantons), however, accounts for around 82 percent of total output (10 percent of U.S. production). Wines from this region are sold everywhere in the country, whereas products of other 16 cantons (mainly sharpish Piont Noirs under various local names, plus good Merlots in the Tessine) don't often find a market beyond their cantonal borders.

Details about some specific names and labels of the ubiquitous Rhone Valley whites will be useful for those planning a visit to Switzerland.

Fendant is the most important. It is widely known, but not - as many assume - synonomous with all Swiss whites. It is a prestige trade name for quality Chasselas wines made in canton Valais, the eastern, and largest distinctive area of production along the Rhone Valley. It is featured on most labels, along with name of producer. Communal names are more conspicuous on bottles of the western, Lake Geneva cantons, where Dorin has significance comparable to Fendant.

Other names from the Valais which add to the "best range" claim are: Johannisberg (Sylvaner grape, with fuller body than Chasselas wines), the limited production, specialty wines Amigne, Ermitage, Arvigne and Humagne (all full-bodied and dry), and Malvosie, which has some residual sugar.

Nor should Swiss reds from the Rhone valley be ignored. Dole and Salvagnin, controlled trade names for quality Pinot Gamay blends, plus Gamays, and some Pinot Noir varietals, can be very agreeable.

Despite limited availability for export, some first-class Swiss wines can be found in Washington. Chasselas whites predominate, but Johannisbergers also get in the act. If you locate any, don't be put off by ages up to 6 years. Despite conventional wisdom about inability of light wines to hold their quality with age, the Swiss wines are an exception. I've had some exciting experiences with many in that age group.