David G. Howell is something of a geological sommelier.
When it comes to the relationship between the land and the wine in California's Napa Valley, he can talk the talk and walk the walk.
It's the spit he needs work on.
In explaining the rationale for his surprisingly popular book, The Winemaker's Dance, Exploring Terroir in the Napa Valley, co-authored by Jonathan Swinchett and published by University of California Press, Howell first wants to clear up his motivation.
"The book was designed not to promote wine," he said, "but geology.
"The only reason I do this wine thing is to get people to think about geology," he said. "The wine aspect is a seductive lure, and once I have them in hand, they must listen to the story of plate tectonics, deep time, gravity and landslides, climate and weather cycles, glaciation and sea level changes. And even resource issues if the spirit is right.
"It's amazing," he concluded, "with the offering to relate wine to geology, they come."
And come they have. The book has been featured in Newsweek and has gotten rave reviews from a territorial central California wine industry that hasn't always embraced outsiders.
The popularity of the effort has surprised Howell, an AAPG member, but he's been through this before ... sort of.
He was known as "Doctor Mud" during the 1998 El Niño, when he was with the U.S. Geological Survey as research geologist in Menlo Park, Calif. But, he said, "Once the daffodils came out and the sun started to shine, the phone went silent."
Knowing a Good Vineyard
Still, climate is one thing; Chablis is another.
He says (quoting from Warren Winiarski of Stag's Leap Wine Cellars) that great wine consists of the three Gs: "ground, grapes and guys."
More importantly, those three elements join in the geological equivalent of a line dance with other factors that make up the Terroir, which is at the center of the book's thesis.
It's simple definition is place, but Howell says while venue is a necessary factor in the understanding of terroir, it is not sufficient.
And then this geologist, a recognized expert on the science of wine, goes into a long explanation of ... art.
"Think of terroir as the provenance of a painting -- knowing the style, the artist, the materials used, who owned it, the museums that exhibited it, how much it sold for -- that's the terroir of painting," he said.
In terms of wine, it would be the ground, the climate, the history -- but also what happened to the area, who owned the land, how often the vineyards changed ownerships, etc.
"Napa Valley," he said, "is like Silicon Valley, in that it's well-defined. It happened to be chosen as an agricultural valley, a mono-culture. It happens to be a great place for wine, and it's also the place where the best minds came. It wasn't designed to be a tourist industry, though certainly that's part of it now.
"Serious people are there, serious farmers, serious scientists," he continued. "In short, these people, their histories, their personalities are all part of the terroir of Napa Valley."
A region, he says, which has a wonderful sense of collaboration and cooperation. A place, too, that is inhibited by people who have one goal: to make the best wine in the world.
"In the '80s it was generally believed that good wine was made in the winery," he said. "The belief now is that good wine comes from the vineyard. Clearly, the land, the person and the grape are all important. All this info impinges on the winemakers, and each dances in a slightly different way.
"I also think the book's illustrations bring to life the otherwise seemingly static view of rocks and dirt."
Napa Valley, unlike its rich relation, the Bordeaux region in France, has been doing this for only about 60 years, and most of what was learned in the years before Prohibition has been lost. California is on a fast learning track.
Howell laughs when asked whether a book like this would have been tolerated in France.
"They're much more certain they're correct about what they're doing over there," he said.
Asked whether they have reason to be, Howell tips his geological hat.
"Well, they make awfully good wine."
Howell has gotten some ribbing -- some gentle, some not -- over what some "serious scientists" consider the book's "popcorn" science.
"By and large, people let me do it," he said. "Besides, I'm retired from the USGS, so I don't have to defend myself."
Howell said he was hoping to de-mystify geology and to explain the process of wine making -- a process, he hoped, that both a novice and experienced engineer would find interesting.
He explains it this way: "Wine has some science, it has lots of art, and frankly the market place evaluates each on a daily basis."
So what of the connection? Does geology have any effect on wine?
"Almost certainly," he says, "but I can't tell you exactly how."
Along the way, however, he made two significant connections between the two.
"Perhaps the most stunning is the occurrence of large mega-landslides and all of the conditions that led us to this conclusion: the hills in the valley, the flat surfaces in the mountains, the low-stands of glaciation to remove the back-stopping debris, etc."
The second, he says, is related and has to do with the east-west compression in the San Andreas system and how it follows the kinematics of a fold and thrust belt.
"It was a buried thrust ramp that elevated the mountains and their pediment surface to a height that exceed their strength, hence the slides."
Still it is the wine that most want to discuss.
Howell believes that wine, itself, is often a misunderstood commodity.
For instance, he says it's hogwash the marketing some wineries do that position the flavor of a wine due in part to the fruit that once stood on the land.
"This is just apocryphal," he said. "The fact there was an apricot tree on the land at some time is meaningless. It doesn't affect the flavor today.
"Wine is clearly alcoholic, but there are people who originally wanted to classify it as a food. It was designed to enhance food and dialog."
But there is, of course, that spitting business.
Admitting he's always been partial to Stag's Leap Wine Cellars Cask 23, he says something both illuminating and revealing about his profession.
"I've always been a typical geologist, drinking the cheap stuff and not knowing any better," he said. "So when I am asked to partake in something like barrel tasting, I mean lots of barrels and some really good stuff, not swallowing seems almost sacrilegious, but it must be done."
"The art of spitting is very complicated. You don't want to drool and you don't want to stain your pants.
"At a wine tasting, I thought I was tasting and spitting. I looked down and saw three of my cups were barely half full; the guy next to me ... all his cups were topped, so yes, though I thought I had made some great discovery, I probably wasn't thinking all that clearly."