Lower Lake, Calif. -- What are the characteristics of winegrapes grown at high elevations? What qualities do those grapes express in wines? Should wineries market these wines as originating from high altitudes?

These were the key questions discussed in an unusual one-day symposium on June 14 at picturesque Snows Lake Vineyard in Northern California's Lake County that featured expert speakers from as far away as Australia, Italy and Argentina. Answers to the first question were lucid, to the second reasonably clear, but the question of marketing remained open at the end of a long day's session that attracted 96 people to sit under a large tent shaded by pines and oaks in the red-soil uplands of Snows Lake, at 2,000 feet above sea level.

Ernesto Bajda of Bodega Catena Zapata in Mendoza, Argentina, gave the most concise presentation of the benefits of high-altitude vineyards, not necessarily breaking new ground for the many viticulturists among the audience, but wrapping up in one Powerpoint presentation the positive effects of high elevation sites on his company's Malbec vineyards. He presented three Catena Zapata Malbecs for tasting, and showed the results of his research on the grapes that made them, grown at altitudes of approximately 2,850, 4,000 and 5,000 feet.

Bajda, an agricultural engineer and winemaker, said his research showed that:

• Harvest-time minimum and maximum daily temperatures both were lower for a Malbec vineyard at about 5,000 feet versus 2,850 feet.
• Total anthocyanins in Malbec went up dramatically with higher elevations.
• Total tannins went steadily up with higher elevations, while bitter monomeric tannins went down.
• Malic acid retention was 2-3 grams per liter higher in the 5,000 feet fruit than the 2,850 fruit.
• Sunlight intensity is higher at higher elevations, resulting in increased photosynthesis and increased production of healthy resveratrol in Malbec.
• Skins were five times thicker at 5,000 feet than at 2,850 feet.

These attributes are generally good for high-quality wines, but sometimes they are too much of a good thing. Leo McCloskey, president of Enologix, discussed several California regions whose wines are highly rated by critics and demand high prices, and demonstrated that Lake County wines, mostly grown at higher elevations than Napa and Sonoma, don't perform as well on these two criteria. In a session on "The Terroir of High Altitude," he said Lake County wines are more tannic, and it hurts their acceptance in the marketplace.

Professor Gregory Jones of Southern Oregon University, a well-known authority on climate as it affects agriculture, spoke during that session, too, pointing out the many and complex climatic conditions that are affected by the geography of a vineyard site, and said that these conditions are often amplified at high elevations. One factor is that the temperature rises 3.6°F for every 1,000 feet, or 1°F for every 275 feet. High elevation sites have lower average temperatures, lower heat accumulation, but higher diurnal temperature fluctuations.

In the keynote address, Randle Johnson, consulting winemaker for The Hess Collection Winery, and director of winemaking at a high-elevation Hess property in Argentina, Bodega Colome, said not only is high-elevation grapegrowing complicated, but it's also very expensive. He quoted Beaulieu Vineyard founder Georges de Latour as saying, "There are three ways to lose lots of money: slow horses, fast women and hillside vineyards."

"Bring a completely open checkbook," Johnson said, if you want to develop a mountain vineyard, because you'll encounter numerous challenges that are multiplied by difficult sites, including: power supply, water rights, environmental impact reports, erosion, rootstock selection and varietal choices. Topping these off, the pressure from insects, birds, rodents, wild pigs and coyotes is often more intense in remote mountain locations. "Planting nice green vines in some of these high desert sites is like putting a buffet in front of the wildlife."

Johnson, who spends several weeks a year in Argentina, said own-rooted vines can sometimes work well in regions with no previous phylloxera exposure. He recommended using only clean plant materials and taking plenty of time to study and design the spacing and trellising, particularly because some high elevation sites can be quite fertile and have deep soils, so one shouldn't assume low vigor in the vines. He recommended two drip lines per row to allow for custom watering and drip nutrition, a possible need for frost protection, and in some places a need for not just bird netting, but fine-mesh wasp netting.

A panel discussion on "Viticulture Up High" was moderated by Glenn McGourty, UC cooperative extension for Mendocino and Lake counties. Speakers on this panel were Vittorino Novello, chairman of the department of viticulture at the University of Torino in Italy; Paul Skinner, owner of Terrs Spase Consulting in Napa; Vince Bonotto, vice president of vineyards for Diageo Chateau & Estate Wines Co. in Napa and Randle Johnson.

Novello described high-elevation winegrowing in Europe, pointing out that Europe clearly defines hill and mountain viticulture using degree of slope, altitude above sea level and existence of terraces. No such definition exists in the United States, and when the symposium's moderator, Peter Molnar, chair, of Obsidian Ridge Vineyard in Lake County, asked the audience for a show of hands on what elevation should the lower limit to be known as high-elevation grapegrowing, no real consensus emerged.

This reporter moderated a panel discussion that started with a presentation by one of Australia's most accomplished and best known winemakers, Philip Shaw, who explained why he chose high-elevation property Orange, New South Wales, for his own winery, upon leaving Rosemount Estate and Southcorp after a long career. Shaw took the opportunity to differ with some of the California speakers who said they or their winery customers needed mountain fruit to have extended hang time to complete flavor ripening after sugar maturity was reached. Shaw said he doesn't follow that trend, and likes to have lower alcohol in his wines without de-alcoholizing. His 2005 Philip Shaw No. 89 Shiraz had good doses of pepper and smoke along with the fruit flavors, like a traditional northern Rhône wine, and was 13.2 in alcohol.

He said he's not afraid of getting too much tannin by picking at 24° or 25° Brix, b ecause he likes the flavors in that range, and will work on the wine in the cellar to reduce tannin effects by micro-oxygenation, increased racking and fining.

A high elevation winemaker and grower from the Sierra Foothills, Bill Easton, also brought Syrahs. His two Terre Rouge wines demonstrated the increase in texture and concentration going from the 1,500 feet elevation to 3,000 feet. Ernesto Bajda offered three increasingly dense, bright and vivid Malbecs going up to nearly 5,000 feet.

The day's last program was on "Marketing, From Mountain to Table," moderated by Paul Wagner of Balzac Communications in Napa, with speakers including Jeff Prather of the Ferry Plaza Wine Merchant in San Francisco; Wilfred Wong, cellar master for Beverages & More and Ronn Wiegand, publisher of Restaurant Wine newsletter.

Wagner asked, "Is there a category of high-elevation or mountain wines in wine shops and restaurants?" Not at Beverages & More, Wong said. Yes, Wiegand said, it's a small niche on some wine lists and it overlaps cool-climate wines. He pointed out that Chianti Classico is an altitude appellation well recognized for quality and price superior to the Chianti region as a whole.

Do consumers ask for high-elevation wines? Wagner asked. No, Prather said, but they do ask regularly for other categories that reflect details of the wine's upbringing, including organic wines, sustainable wines and biodynamic wines.

Wiegand said that food-friendliness is why he recommends high-elevation wines in his newsletter and to the restaurants he advises. He looks particularly for fragrance and for a refreshing quality in these wines. Prather added that he believes alcohol content is "out of control, and that wineries "are going for scores, we're not going for wines that go with food."

Peter Molnar wrapped up the day's presentations, saying that the second such symposium will be in two years, and "I hope this is just the beginning of the collaboration that we talked about today." He said that plans regarding research on high-elevation wines will go forward. More information is available at theelevationofwine.org.

The symposium's key sponsor was the Lake County Winegrape Commission, and Snows Lake Vineyard was also a big supporter. Sponsoring vineyards and wineries were: Beckstoffer Amber Knolls, Bella Vista Farming, Brassfield Estate, Nova Winegrape Brokers, Obsidian Ridge, Shannon Ridge, Six Sigma and Spencer Roloson, along with the Tallman Hotel.