Because the best white wine grapes have complex aromatics that oak can stifle, some wineries are throwing over their wooden barrels and fermenting their products in stainless steel instead.

THE MARRIAGE of wood and wine, which remained stable for close to 200 years, has suddenly, dramatically changed. The dependable French oak barrel, long the Cadillac of wood for fermenting and aging both red and (some) white wines, is being challenged.

Wineries are using oak staves, oak chips and even oak powder to impart the friendly flavors of new wood to young wines. A company called Boisé France makes "barrel alternative oak products" (oak chips) in a menu of flavors right out of Starbucks: "Seasoned Untoasted," "Single Chauffe Standard Blend," "Double Chauffe 180" and so on. Make that "to go," please!

As if oak chips weren't enough to leave traditionalists over a barrel, the biggest challenge of all is coming from — where else? — Down Under, where they are 86-ing the wood altogether. The marketing of Australian and New Zealand white wines labeled "unoaked" or "unwooded," once a trickle, has turned into a trend. And a trendy trend at that.

The best white wine grapes have complex aromatics, and much of the pleasure in wines such as riesling, gewurztraminer, sauvignon blanc and pinot grigio comes from these subtle scents. Oak often obliterates such nuances. It can make wines too heavy and difficult to match with food. The switch to unoaked wine-making puts the natural flavors of the grape front and center, and also highlights nuances of the soil, particularly in places such as Sancerre and Chablis.

Granted, most vineyards are not blessed with soils so complex and minerally, and chardonnay, the most commonly found "unwooded" wine, is not among the most aromatic of white wine grapes. It's not easy to pinpoint just what exactly chardonnay does taste like. If you think of chardonnay as buttery, toasty, nutty, perhaps tasting of vanilla, coconut or spice, you are describing the flavors of the barrel, not the grape. Unwooded chardonnays are designed to show you what the grape itself tastes like.

Peter Leske, winemaker for Australia's Nepenthe, writes that his unwooded/unoaked chardonnay is made "as a contrast to the considerably bigger, richer, often somewhat overpowering styles that feature more winemaker intervention — wines that sometimes reflect winemakers' egos and ideologies rather than the grapes from which they are made."

It's not just about flavor — economic forces are also driving wineries to make wines that are more limber, less lumber. The cost of French oak barrels is becoming prohibitive as the Euro bulks up. Unwooded wines avoid those costs, and they are usually released earlier, another plus for the bottom line.

For consumers, there are advantages beyond price. Unwooded chardonnays, properly made, retain more freshness than their planky brethren. They keep their lively acids, which extends their useful lifespan. They are often made from cool-climate grapes, so the wines have moderate levels of alcohol yet offer complex, layered flavors. They match well with food and even (gasp!) retain some delicate aromas not usually associated with chardonnay.

No legal guidelines regulate the use of terms such as unwooded or unoaked, but you may reasonably assume that wines so-labeled have not been fermented or aged in wood, nor have they been chipped, staved or powdered.

White wines such as riesling and gewurztraminer will rarely be labeled unoaked because fermentation in stainless steel is the norm, not the exception, for these wines. But chardonnays, sauvignon blancs and semillons are often barrel-fermented and/or barrel-aged. Those are the wines most likely to declare themselves unoaked, unwooded, virgin or oak-free.

Starvedog Lane is another cool-climate Australian producer committed to the concept. Owner John Edwards puts "No Oak" on one chardonnay to differentiate it from his regular chardonnay. "It's like chalk and cheese comparing a traditionally-oaked chardonnay to an unoaked one," says Edwards.

"Unoaked chardonnay displays the true fruit flavors of this variety, without the tricks and treatment of wood. It is so different it could almost be another varietal."

I agree. The rainbow flavors of unwooded chardonnays can run from green apples, pears and fennel right into apricots, papayas, guavas and pineapples. Fruity, but not flabby.

These wines often come in screwcaps, another tryout turned trend first popularized in Australia. Screwcaps ensure that the risk of a bad cork is eliminated. Serve these wines at around 45 degrees, midway between refrigerator and cellar temperature.

Paul Gregutt writes the Wednesday wine column for The Seattle Times and teaches wine-tasting seminars. He can be contacted at tastesmart@aol.com. Barry Wong is a Pacific Northwest magazine staff photographer.