The hottest wine varieties in the world, are Chardonnay, Merlot, Cabernet Sauvignon and, here in the U.S., White Zinfandel.

Of California wineries which have tasting rooms, the most popular wine sold in those tasting rooms very often is Riesling, Gewurztraminer, some kind of Muscat, or perhaps White Zinfandel, all wines with small amounts of residual sweetness and lots of fruit flavor. With the exception of the White Zin, none of those wines are anywhere near the top of anyone's retail best seller list.

So why do they sell so well out of tasting rooms? Simple. They taste good. I'm not saying that Chardonnay, Merlot and Cabernet don't taste good, but in addition they are in vogue and have a cache about them.

Riesling had that charisma going for it 20-25 years ago, back in the days when "Blue Nun," "The Bishop of Riesling," "Zeller Schwarze Katz," and "Piesporters of one type or another," were moderately priced German wines that dominated the white side of wine lists everywhere and that people loved to share with their friends.

California wines labeled Johannisberg Riesling were nearly as popular.

But Americans have a habit of making fun of those wines which are most successful, to the point that folks become self-conscious about drinking them.

White Zinfandel is one of the few survivors, and many of its original fans have switched to more fashionable fad wines, like some of the new drier roses.

If you're old enough, you'll remember when Mateus and Lancer's roses from Portugal were all the rage and on virtually every wine list in America. Then they became the butt of jokes, and were soon forgotten.

Older than that? Remember Grenache Rose? Not quite so old? How about Cold Duck followed by "pop" wines the likes of Spanada and Boone's Farm? And who will ever forget the wine that tasted like "7-Up?", "Tyrolia."

The reason that Riesling (and Gewurztraminer, Muscat and White Zin) sell so well in tasting rooms is because people are buying based on what tastes good and not image or marketing hype.

What inspired this tirade?

In a move that can only be called self-serving (but very, very smart), the German Wine Information Bureau is conducting the "Riesling Challenge" on wine drinkers age 21-36 in trendy restaurants. The tasters are given tastes of three whites, one of which is always a Riesling, the other two are usually a Chardonnay and a Sauvignon Blanc. When the decision is based on taste, Riesling rules by a large percentage, especially with occasional drinkers.

If you're one of those folks who think you don't like wine, ask a wine merchant to recommend a Riesling from Germany, Austria, New York, Washington, Oregon or California. The flavors range from crisp green apple, to riper apple flavors, to pears, to a variety of stone fruits like peaches, apricot and nectarine. And sweetness ranges from green apple-tart to literally as sweet as anyone can stand.

For more information on German wines in general, contact: German Wine Information, 245 Fifth Ave #2204, NY, NY 10016 (212) 896-3336; E-mail: sullassoc1@aol.com

SPEAKING OF PREDICTIONS

Everyone in the industry saw it coming, so I'm not claiming to be some kind of wizard, but I also told you last fall to expect a huge crop, partially due to a near perfect growing season and partially due large plantings that had been going in over the past several years in response to both shortages and to damage from the rotten little root louse phylloxera.

I hasten to add that wine grapes historically go through periods of boom- bust in California and have since gold rush days.

In the 60s there was so much demand for white wine that wineries tried desparately to make white wine out of red grapes (resulting in the birth of White Zinfandel which is really pink, blanc de noirs, and so on), and when Chenin Blanc was even harder to come by than White Zinfandel was a few years ago or than Merlot has been recently.

So just when growers got enough Chenin Blanc planted, what happened? Consumers lost interest, and discovered Chardonnay. Growers pulled up Chenin (and all kinds of red vines) to plant Chardonnay, and of course consumers wanted red wine, partially because of health reports and partially because they had discovered the softer flavors and tannins of Merlot. So guess what? Merlot tonnage jumped by an amazing 89 percent in 1997, making my prediction of White Merlot and Merlot in bag-in-box seem like a sure thing. Did I mention that Sutter Home has already announced a Merlot Rose?

What does it all mean? With everyone planting Merlot, consumers are no doubt going to change their tastes again. Maybe to the Riesling mentioned in the previous item?

BEST BUY WINE OF THE WEEK

Adler Fels 1996 "Coleman Reserve" Chardonnay ($16) Best known for medal- winning Fume Blanc and Gewurztraminer, eccentric winemaker David Coleman has added yet another variety to his collection of wines he does as well as anyone in the business (his 95 Sangiovese is also a guaranteed gold medal winner this year). This smoky, toasty, rich in oak vanillin white wine still manages to be crisp of acid with attractive citrus notes that prevent it from being flabby and insure that it will be a dandy food companion. Broiled swordfish or halibut are the first things that come to mind. To track down Adler Fels limited production wines: 5325 Corrick Lane, Santa Rosa, CA 95405 (707) 539-3123; E-mail: adlerfel@pacbell.net Rating: 90/90

Wines are scored using a unique 100 point system. First number rates quality; second number rates value.