Every serious winemaker says the secret of great wine is great grapes. Intrigued, wine editor Lettie Teague attends a grape-growing seminar at the famed University of California, Davis.

I've always wanted to go to Harvard. At least I've always wanted to be able to say I went there. Instead, I graduated from a liberal arts college in Ohio that some people call the Harvard of the Midwest. (Never mind that most of them are alumni.) There's a Harvard of winemaking too—the University of California, Davis—though no other university in the country even comes close to matching the reputation of its school of oenology. In fact, it seems as though every great American winemaker calls UC Davis his or her alma mater.

I've thought about Davis, as it's familiarly known, over the years—imagined its bucolic, vineyard-covered campus and conversations among its future winemakers. ("Is $300 too much to charge for a Cabernet?" or "Do you think this Chardonnay could use a little more oak?") But it never occurred to me that I could be a student there. Then one day a brochure arrived in the mail announcing a Davis Extension course in varietal wine grape production, open to professionals and amateurs alike. The three-day program, taught by both Davis professors and experts in the field, promised to give attendees an "intensive, in-depth look" at the basics of grape growing and vineyard development and management.

What could be more perfect, I reasoned, or for that matter, more timely, than taking a course in viticulture? After all, nearly every serious winemaker I meet tells me it's the grapes, not the winemaking, that matter the most. "It all happens in the vineyard," they like to say. What better place than the campus at Davis to find out if this is true?

The program's director, Jim Lapsley, seemed surprised by my call. "This is a course for people who are already in the business or are seriously interested in developing a vineyard," he said, sounding skeptical. While I admitted that my suburban half acre wasn't a promising vineyard site, I thought there was still plenty that I could learn. And of course there was the appeal of simply being at Davis and walking through its fabled vineyards. (I figured such field trips would be frequent, given the subject matter.) Lapsley said he'd get back to me. A few weeks later, he called to say I was in.

Having thought Harvard for so long when I heard Davis, I was taken aback to discover how little the two actually have in common. At least architecturally. Instead of Harvard's historic, ivy-covered brick buildings, the entire Davis campus looks like it's been poured from the same bucket of concrete. (The word one faculty member used to describe it to me was glum.) There isn't a vine, let alone a vineyard, in sight. (The Davis vineyards, I later discovered, are nearly two miles off campus.) Worse yet, when I arrived at 8:30 for my first morning class, the registrar had no record of me.

"I don't see your name," she said, looking at the tags laid out on the table and the names on her list. I scanned the tags too, checking the names and professions of my fellow students. As Lapsley had predicted, many seemed to be in the wine business already, representing wineries such as Gallo, Woodbridge and Phelps. Some appeared to be changing careers (like the woman who registered from Guide Dogs for the Blind), but in either case, they came from all over—California to Vermont.

The name-tag woman conferred with a colleague and slipped me a blank tag and a pen. "Just write in your name," she said conspiratorially. It took a little more time to convince her to give me the curriculum—a big three-ring binder stuffed full of material, not unlike the sort I'd carried back in seventh grade. She finally relinquished the binder, but gave me this warning: "You'll have to give it back if someone else needs it" (which, coincidentally, was pretty much my same status as in the seventh grade).

According to the program, all three days of classes (25 in total) were scheduled to take place in Freeborn Hall—the field trips, I imagined, would be announced individually. Freeborn Hall looked less like a lecture hall and more like a gym, albeit one filled with metal tables and chairs. When I took my seat in front of two men chatting about Chardonnay, more than one hundred would-be viticulturists were already in place, furiously flipping through their plastic binders.

Lapsley, a professor of vineyard and winery economics, delivered one of the first lectures of the morning, an overview of the wine grape industry. (When I introduced myself to him later that morning and remarked on the number of professionals enrolled, Lapsley nodded and said, "I saw them in the audience; the real grape growers are the ones wearing vests." I'd thought the vest wearers had just been in Freeborn Hall before, since the room temperature seemed to hover around 55 degrees.)

Lapsley opened his presentation with a bleak observation—"Wine is a marginal beverage"—and followed it up with some depressing statistics: Wine represents less than 1 percent of all liquids purchased in the United States; a small group of people (10 percent of the adult population) in this country actually consumes 90 percent of the wine; and nearly all that wine costs $8 or less. Naturally, the grapes that go into these wines don't command very high prices.

The message behind such statistics, said Lapsley, is that grape growers have to "figure out where their grapes belong" and do all they can to differentiate themselves. "Take a lesser price for your grapes if the winery you're selling to will put your vineyard's name on the bottle," was one piece of advice Lapsley offered. (Is that why so many wineries are turning out vineyard-designated bottlings? Not because the vineyard is great, but because the grapes come cheap?)

It certainly was something to think about—but there were plenty of other revelations at hand. Like how much math is involved in growing grapes. When one of the university's farm advisors spoke on the subject of selecting a vineyard site, she didn't talk (as I thought she might) about finding the right real estate agent, but rather about learning mathematical formulas. Grape growers, she said, flipping her slides, have to be familiar with all kinds of formulas—including the formula for a vineyard's slope relative to its aspect, not to mention the formula for its climate or "degree days" (DD = (Tmax + Tmin)/2 - 50 degrees). As my fellow classmates dutifully copied the figures into their notebooks, I couldn't help wondering how much they really understood of what they were writing.

I decided to conduct my own informal poll—starting with the man standing behind me in the line for lunch. He turned out to be a professional, a chemist working in a wine analysis lab, and therefore he understood just about everything that had been said. He was, however, hoping to get a few pointers on improving his Petite Sirah vineyard. Where was the vineyard? I asked. In Petaluma, he answered. (He was a grape grower in need of a real estate agent.)

We joined a group of students working their way through the steam-table spaghetti. When I asked what they thought of the lectures so far, one woman admitted that she and a friend had come just to "learn the lingo," since both of their husbands had recently purchased vineyards. I pictured them trying to talk climate formulas over cocktails. A man who was applying for a winery permit understood a few things—he'd been coming to Davis for years. Another man owned a winery in Napa where he employed a "very famous winemaking consultant." He had also been to Davis before and pronounced its seminars worthwhile, "even if you only learn one or two things." I started to ask about field trips, but he was already on his way back to class. In the meantime, I noticed that no one was drinking wine—or for that matter, had anything stronger than tea.

The classes moved along at a rapid pace, with just under an hour devoted to each subject: vineyard spacing and trellising, vine training and pruning—all things I knew a little something about but had never studied before in such an intensive way. And there was yet more to cover: soil fertility analysis and soil amendments, not to mention frost protection and vine nutrition—all inevitably illustrated by slides of men riding tractors. The students around me copied everything down with a passion, showing no sign of fatigue.

The class became downright lively when the subject turned to irrigation. In fact, irrigation was of such considerable interest, it was accorded two separate seminars (irrigation systems and scheduling irrigation). Even seminars that were seemingly unrelated to water managed to get back to it somehow. The soil fertility expert, for example, had a word for conjoining the two: fertigation. I imagined the two women trying to figure out how to get that into their next cocktail party chat.

Although irrigation was the subject that most excited the audience—I'd never heard so much talk about water since the movie Chinatown—the seminar that intrigued me the most had to do with grapes and clones (mutants of grape varieties bred for certain characteristics like size, weight, color and flavor). I was interested not only because Davis does some of the world's most important research work with clones, but also because the subject seemed like a perfect excuse for a field trip. Lecturer Jim Wolpert (a Davis professor with an unwieldy title—Extension Viticulture Specialist) began by addressing the demands of the market. Grape growers, he said, have to plant what will sell. He also recommended choosing clones that are "fashionable"—ones that the winemakers want.

He endorsed the idea of planting Syrah, which he thought had great potential. The same was true of Viognier, though on a much smaller scale. "If you plant 100 acres of it, you're out there by yourself," he warned. On the other hand, Wolpert couldn't say a good word about Chardonnay, of which there is a considerable glut. "We've had growers call the university and ask if they can donate their 30 acres of Chardonnay for a tax write-off," he said, soberly adding—in an echo of Lapsley—"It's tough out there." I pictured Chardonnay growers trying to barter their grapes at the grocer's, the hairdresser's and the dry cleaner's.

The third and last day of class was devoted to rot, pests and viruses ("vineyard infestation"). If there was a field trip for these, I didn't want to be on it. I decided to cut class and have a look around town. I figured there were probably some interesting wine shops and a few funky wine bars serving student-made Syrahs, Cabs and Viogniers. But after three trips around the whole town (Davis, which is about 15 miles west of Sacramento, is quite small), I found only taco parlors and hamburger joints, used bookshops and nail salons. Finally, I consulted the phone book and found exactly one wine bar and one wine store downtown.

The wine bar looked as though it had gone out of business ("The owner only opens when she feels like it," I was later told), while the wine shop looked like it was barely surviving. Why was there so little wine business in town? I asked the shop's proprietor, who, in an effort to boost sales, had added chocolate and potato chips to his half-empty shelves. "Academics are cheap," he replied. "They buy their wine from wineries where they get discounts." A waiter at a nearby restaurant featuring "wine country cuisine" told me much the same thing: "People here just don't seem to care much about wine."

I returned to Freeborn Hall just in time to see the instructor flip to a slide of a fierce-looking bug. Magnified, it looked like something from a horror film. My hands grew clammy as she described the damage and economic devastation it wrought. Meanwhile, the would-be growers around me were silent, entranced.

Grape growers are remarkably tough. Their troubles appear greater than Job's (irrigation leaks, infestations, frost and, of course, math), but they seem to rise, untroubled, above them all. And though I never saw one Davis vineyard, I learned a lot about grape growers and why winemakers so eagerly credit the work they do. Every week, every hour, every minute, a grape grower has to be mindful of what's happening in the vineyard—while a winemaker has to get it right just once a year.