YALUMBA'S success with the viognier variety in Australia has been a lesson in passion and determination.

When Yalumba's director of winemaking, Brian Walsh, started with the company 20 years ago, he admits he hadn't heard of the grape variety viognier. The white variety that hails from France's Rhone region had been planted in 1980 as a trial and it had yet to be assigned full duties within the Angaston-based winery's list.

The vines were growing quietly in the background, allowed time to find their cropping patterns and for Yalumba's winemakers to figure how to treat the variety.

They were Australia's first commercial plantings. Their French forebears were, by then, confined to only the small Rhone appellations of Condrieu and Cote Rotie.

As Riesling makers first and foremost, Walsh recalls, they made viognier in much the same manner, picked at lower grape sugar levels, cool fermented for a clean and crisp wine that eventually found its way into a mass volume dry white.

Soon they discovered that the grape could offer something more. When Yalumba's team saw more and more from the variety in its homeland, Walsh and his gang took up the challenge.

"We saw different people doing decent things with it, and getting different textures, so we thought we'd try to emulate that," Walsh recalls.

The grapes were left to ripen further, and the winemaking took on decided French fermentation and maturation techniques.

"Suddenly we thought what we had was terrific. We were getting a new flavour expression which wasn't like chardonnay nor anything else in the cellar, and we had different (glycerol/unctuous) textures, and a combination of aromatics on the nose and savoury characters on the finish.

"We were pretty excited."

A decade and a bit on and Yalumba has become the "viognier company", with five white versions and a trio of red shiraz-blends using small additions of the white grape for added aromatic lift and mouthfeel.

The 2006 white varietal releases are a showcase for how far the company has come, having set itself the challenge of finding a signature white to partner its Octavious shiraz, as well as creating an entry and intermediate-level table wine and a sweet version.

With hindsight, Walsh says viognier was the logical choice for its signature white, called Virgilius, even when other major companies were heading towards chardonnay. The variety's Rhone history was an obvious comfortable match with shiraz.

With the Virgilius, more detailed work in Yalumba's Eden Valley vineyards as well as focused barrel selection gives the wine a sporting chance at fame, and maturing for a few years in the bottle.

Walsh's team, which includes head winemaker and arguably the country's No. 1 viognier specialist, Louise Rose, direct juice straight from the press to barrels, so each barrel is slightly different as it takes up indigenous ferments from wild yeasts.

From 60 separate ferments, the best 30 or so are selected for a combination of their aromatics and intensity as well as structural tautness.

There are definite stone fruit and honeysuckle aromatics, with an underlying Asian mint/Thai basil character, too, that give the wine an exotic personality that even shows some gingery oak elements. The variety's typical unctuous texture is evident and there's some minerality as well as a lovely lift of acidity to finish.

The remaining barrels that don't go to Virgilius are headed into the next level, the Eden Valley range, which in some years challenges its flashier sibling for top points.

The entry level Y Series is proof that the variety can do well out of a range of climates, with surprisingly strong varietal presence and an obvious richness from mostly Riverland fruit.

"It's unmistakably viognier - grown in a hot climate," says Walsh. "It seems to like the warmth."

The sweet style comes from plantings in the Limestone Coast's Wrattonbully district, the late-harvest botrytis version ($25) offering classic apricot and marmalade characters without over-the-top sweetness. This restraint seems to be a house feature of the Yalumba whites, yet in the Y Series shiraz viognier, Walsh says it was time to ditch the subtlety and tell the viognier story as it influences the shiraz.

The result is a softened style, not only in the flavours but in the texturals, showing quite a harmonious style with a mouth-watering effect - as if you want to eat there and then.

"You've got to say the shiraz-viognier business is not an exact science," says Walsh, referring to the several ways the two varieties come together, including co-fermentation and the addition of viognier skins into shiraz ferments.

Winemakers are finding surprising co-pigmentation results as well, he says. "If you put the white grapes in with the red, the white makes the combination more red," he explains.

When it comes to flavours, viognier gives a lift to ripe shiraz, especially, Walsh says, from warmer areas where the red sometimes needs livening.

He doesn't shy away from spelling out viognier's role on the label with the shiraz, as the style has become a distinct wine in the marketplace and it tells of Yalumba's pride in being "the viognier company".

Not afraid to stack up his whites especially against those of the adored Condrieu, Walsh's team believe their strength has been to offer a complete experience from the variety, from a high-end viognier to an entry point.

"We get exceptional expression from the variety at all price points," Walsh says.

"I think we are the most influential viognier producer in the world."