Wine-loving China, the world's fifth-biggest consumer, is not known for making top-quality wine but its potential is drawing elite vintners like Spain's Torres and France's Lafite.

"We are looking to make the best wine possible, but not necessarily the best wine in the world," said Gerard Colin, managing director of Lafite's wine estate in China.

Colin spoke on a hilltop on the Penglai peninsula in eastern China's Shandong province as a bulldozer flattened ochre earth into neatly terraced vineyard plots.

Nearby, peasant farmers cleared stones from a future vineyard, masons sculpted the hillside with dry-stone retaining walls and created catchments for natural springs in case of drought.

Orchards, peanut bushes and vineyards stretch across the surrounding valleys. A 560-hectare (1,384 acre) no-build zone surrounds the 25-hectare estate.

According to the International Organisation of Vine and Wine (OIV), China is not only wine-thirsty but is now the world's sixth biggest wine producer, edging out Australia.

Driving his beat-up four-wheel-drive along a perilously rutted road, Colin nods a greeting to the village shaman resting in a field and pulls up next to the site of the future four-storey, gravity-led winery.

"It's not a huge project, but it's a long-term sustainable project, and truly the creation of a terroir and a cru, and we're taking the time necessary," said Colin.

For now, the location of the ideal Chinese terroir - that combination of soil, climate and human expertise that creates the legendary wines of places like Bordeaux and Burgundy - remains a mystery, and the obstacles to finding it are great.

"Chile is the El Dorado for easy winemaking," Denis Dubourdieu, professor, researcher and winemaker, told AFP in Bordeaux. "China is not that."

"The north is too cold, the south too hot, and monsoons during July and August threaten to yield unripe or rotten crops.

"These are complications," said Dubourdieu. "They are not insurmountable, but the best zones for viticulture in China are not obvious."

Quality-control problems also are an issue.

"The big five wineries occupy 90 percent of the market and drive it by quantity rather than quality," said Alberto Fernandez, the Shanghai-based managing partner of Torres China, one of the three largest distributors operating in China.

"The domestic fine wine side is less than one percent of the total wine produced."

At the moment, the best hope for quality wine in China comes from a handful of family-owned vineyards, two of which collaborate with Torres China, Grace Vineyards and Silver Heights.

But the vast majority of Chinese domestic production appears to be following the Australian model of industrialised production of brand wines.

Brand wines succeed with a combination of savvy marketing, easily deciphered labels and consistent quality.

Chinese brand wines, however, are notoriously inconsistent in quality, and some producers pay little heed to Western notions of truth in labelling.

From one year to the next, domestic Chinese wine with the same label is a varying blend of wine produced in the local region, wine shipped in from other Chinese regions, low-grade imported bulk wine, and any available vintage.

None of this appears to diminish China's enthusiasm for wine.

In 2009, China drank 1.2 billion bottles of wine, and only 8.5 percent of that was imported bottled wine, according to Torres China. The surface area of domestic vineyards increased by 6.1 percent from 2006 to 2009, and grape production increased by 10.7 percent, according to the OIV.

"We know China is growing very fast and producing a lot of wine even if the quality is so-so," said internationally renowned winemaker Michel Rolland.

"But I think every country in the world, if we go back a long time, made so-so wine at one time.

"China is just beginning and the Chinese are not stupid. They will be able to produce very good wine in the near future."

But it won't happen overnight.

Christophe Salin, the Lafite group's managing director, told AFP that they have spent 15 years looking for the right opportunity in China, five years studying the chosen site, and do not expect to release any wine before 2015.

Until then, no one knows if they've invested in the right spot.

Despite the risks, the undiscovered potential of China's terroirs lures the West.

"If I find a very exclusive project where somebody is really focusing on the search for where we can go in terms of quality in China, I would like to do that," said Rolland.

"I don't want to make a huge project with a large number of tanks where we taste like crazy for two days to make the blend. I have done that my whole life and I don't need that anymore. But if I can find that exclusive project, maybe I'm going to China."