TUNNEL VISION : European vintners have long used caves to store their wines. Today, Napa Valley wine makers are rediscovering the benefits of this natural, ‘low-tech’ technique.

In the world of wine making, tradition occasionally wears like an albatross, and the latest “in” thing in the Napa Valley appears to be another concept that is more form than substance: cave dwelling.

Wineries up and down the valley are digging holes in the ground and moving their wine--lock, stock and barrels--into them. And one man is doing almost all the digging.

Alf Burtleson is the beneficiary of all this renewed interest in back-to-the-earth wine storage. His Alf Burtleson Construction Co. has done 90% of all the digging for winery caves in the last few years and his firm has yet to have a slack period.

“The phone keeps ringing,” said Burtleson. “The interest in caves seems to be growing faster than last year.” He estimates that there is a waiting list sufficient to keep him busy for three years.

To date he’s done 22 cave-digging jobs for 19 wineries, almost all of it in the Napa Valley. He recently accepted second jobs at Sterling, Schramsberg, Clos Pegase and Rutherford Hill, and he’s now working on a third project at Far Niente.

Unlike so many traditional concepts, however, this recent interest in caves is not merely an excuse to emulate our ancestors. It’s for a much sounder reason. It saves wine and that saves money.

On first look, though, it appears that this move back to nature is little more than cosmetic--an attempt to recreate the romantic notion of wine as the ultimately basic product. It is, after all, little more than crushed grapes that have been converted by fermentation. It’s so natural that it could make itself if a bunch of grapes fell into a trough.

Little in that “formula” has changed in centuries; it’s still a one-ingredient product. All that’s changed in the centuries is the addition of technology, the use of such things as air conditioning systems to keep the barrels cool as they age in tilt-up concrete block warehouses called wineries. (Heat can turn fermentations awry, producing strange offshoots of wine, such as vinegar.)

In Europe, however, before the advent of air conditioning, the cognoscenti used caves to keep their elixir cool. In European wine caves, the natural underground temperature was constant and cool and helped the wine mature gracefully.

Air conditioning worked almost as well, but there is one major drawback: evaporation.

“The cost (of using air conditioning) really is in wine evaporation,” said Burtleson. “If you checked the condensation coming out of a winery air conditioning system, you’d find there’s alcohol in it. They’re losing wine out of the barrel. But with your cellar underground, there’s very little evaporation.”

After Burtleson did one tunneling job to create wine caves for Rutherford Hill Winery, “they moved all their barrels inside and later they told me they were saving one case per year out of each barrel.” A 5% annual saving means that a winery that ages its wine in barrels for two years would save 10% from evaporation. Evaporation in a wine cave is reduced to an estimated 2% per year.

A winery with an annual production of 10,000 cases of Cabernet Sauvignon would show a net gain of 600 cases after two years of barrel aging in a cave setting over that in an air-conditioned building. Moreover, there’s a saving realized from no electrical bill to air-condition a cave.

“These are the most ideal conditions known in the wine industry,” said Gil Nickel, owner of Far Niente Winery in the Napa Valley, the first man to hire Burtleson for a start-up wine cave project a decade ago. “The temperature in here is 58 degrees, plus or minus two degrees, which is perfect for wine storage, and near 100% humidity.”

(The high humidity can generate a lot of mold on barrels and walls, necessitating a lot more cleaning.)

Burtleson, a student of the geology of the Napa and Sonoma valleys, can trace the areas that have volcanic soils and which areas are composed of the Franciscan geological formation, which is more difficult to work on because it’s more fractured, with shale and sandstone presenting different problems than volcanic rock.

Burtleson founded his construction company in 1964 in San Francisco, digging tunnels for freeway, utility and drainage projects. His firm moved to Sebastopol in Sonoma County in 1972 and it was then that things began to change.

Nestle had bought the old Beringer Winery in the Napa Valley that had extensive wine aging caves dug into the hillside. But the caves were in disrepair so Beringer hired a construction company to repair them.

“The work started and the caves began caving in, so Beringer decided to get someone who knew what they’re doing,” said Burtleson. “We were a smaller tunnel contractor, but we knew the problems. We finished the job. Then Gil Nickel called and asked if we could do one from scratch.”

The first Far Niente project seven years ago (a small 60-by-10 foot cave) led to another cave project, and a third was started earlier this year. It should be finished by December. When it’s completed, Far Niente will have 15,000 square feet of space underground, nearly doubling the usable space of the winery without affecting the historic (founded: 1885) visage of the original winery.

A year ago, Burtleson moved his construction company to Calistoga, at the northern tip of the Napa Valley, because most of his recent work has been in the Napa Valley.

“This is the most incredible construction project I’ve ever seen,” said Nickel. “It’s not the largest cave project, but I’m certain it’s the most elaborate. We’re adding lighting controllers that will give us four predetermined lighting arrangements, so you can have soft lighting for mood and bright for production and stages in between.

“The caves vary in width from 12 1/2 feet to 24 feet; there’s one round room that is 30 feet across; we have an octagonal room for wine storage and tastings. And it’s gonna be really magical because we’ll have an entrance at the far end that leads out onto a flagstone patio with an open grotto and balustrades.”

Burtleson said one of the more intriguing projects he’s done is for wine maker Ric Forman. It is 100 feet down below Forman’s house, with the only access from Forman’s vineyard down the road from the house.

A well-driller dug transfer lines to accommodate pipes as well as electrical lines.

To date, most of Burtleson’s work has been done for wineries owned by the wealthy, those who make high-end wines, even though the cost of constructing a cave is no more than the cost of building a standard concrete building for a winery.

Burtleson said he could do a bare-bones cave project for about $30 a square foot, but that typically his charges run about $40 to $50 a square foot, rarely above $60.

Cost for construction of a standard concrete building runs $40 to $50 a square foot, though some winery owners feel you can’t do one for less than $75 a square foot and still have modern-day functionality.

“We’ve done caves that cost more than $100 a square foot, like at Far Niente,” said Burtleson. Included is special flooring, lighting and other architectural and design features that make the cave look more like part of a winery building.

The procedure of digging a tunnel requires a machine, called a roadheader, that’s used in coal mining. Burtleson’s roadheader operator is Dale Wongergem, who sits well above the cave floor on the machine. Ahead of him is a huge tooth-studded grinder poking out from underneath the front of the machine and 20 feet in front.

The grinder, which looks a bit like a mace, rotates and eats into the rock. As the rock and earth crumble, they are carried back behind the roadheader by conveyor belts to the rear of the machine.

A ventilation system for the operator is critical, and workers wear ear plugs because of the intense noise generated by all the gears working at one time--ventilation system, roadheader, conveyor belts.

“Dale Wongergem is, well, he’s a gem,” said Nickel. “He’s a real Rembrandt on that coal mining machine, and Alf is one of those guys who do more than you ask. He’s wonderful. This is a great crew.”

But it’s Burtleson’s only crew. He has rejected suggestions that his company grow by adding more workers and taking on more work. Burtleson said he tried that once and it didn’t work.

“I’ve been in business 25 years and I know how big companies operate and I know how small companies work,” he said. “And the quality of the work is the most important to me. Once I had two crews, and usually one crew or the other had problems, and I was spending all my time dealing with problems. This crew I have now is excellent, and I can monitor what happens every step of the way.”

As to the possibility of cave-ins, especially in California where earthquakes are not uncommon, Burtleson says, “We’ve never had a cave-in. With our method, there’s about 20 feet between the operator (of the digging machine) and the front of the machine, so if there is any over-break, we simply shot ‘crete,” which is to shoot concrete onto the walls to firm up the earth.

Nickel said, “Alf says that if a cave lasts three weeks it’s likely to last a few thousand years.”

Gross revenues for Burtleson Construction are “still under $1 million. This is not a big business,” said Burtleson. He pointed out that even though wineries all over California’s north coast want projects started, few competitors have come into the field.

“There are others who do this, we can’t do every job, and people want caves so bad they’ve hired other people,” he said. He noted that Atlas Peak Vineyards, the joint venture between Whitbread of England, Antinori of Italy and Bollinger of France, hired its own crew for its cave project.

However, Burtleson’s waiting list of wineries hasn’t shrunk. “I guess people like what we do,” he said.

Nickel said he got the idea for the caves after traveling to France and seeing the tunnels of Bouchard Pere et Fils, which stretch some seven miles. He said he designed his tunnels to be the most dramatic in the world.

But then Nickel, a good-natured transplanted Oklahoman with an easy Southwest drawl, laughed and added, “It’s kind of like fishing. The first liar doesn’t stand a chance.”

Burtleson and his wife, Mary Jane, recently moved into a home adjacent to an old, abandoned winery in Calistoga and he is digging himself an underground, cave-entrance wine cellar.

“I want to have a fancy wine cellar, something like no one else has,” he said.

Even Burtleson has been attracted to this latest craze.