The following is an excerpt from Frances Dinkelspiel’s Tangled Vines: Greed, Murder, Obsession, and an Arsonist in the Vineyards of California.

One of the largest cases of wine fraud in the United States happened in 1987, and Steven Lapham, who would prosecute Mark Anderson twenty years later, was the assistant U.S. attorney spearheading the case. Interest in California wine had exploded in the late 1970s when a young winemaker named Bob Trinchero accidentally created a sweet, light pink wine he called white Zinfandel. Trinchero had been pushing his father Mario, the owner of Sutter Home winery in St. Helena, to plant more Zinfandel grapes. Zinfandel had once been one of California’s most popular varieties, but had fallen out of favor after Prohibition. Trinchero was one of a new group of young winemakers who saw potential in the grape. He loved its dense, fruity flavor. But Mario was skeptical, and only grudgingly allowed his son to proceed.

Ridge Vineyards and Mayacamas Vineyards had also gone into Zinfandel in a big way and Trinchero wanted to make a wine that was better than theirs. In an attempt to enhance his Zinfandel, in 1972 Trinchero crushed the grapes and drew off some of the juice before the wine started to ferment. The French call this process saignée. It intensifies the color, body, and flavor of wine by decreasing the amount of juice relative to the amount of skins. The pro cess worked: the Sutter Home 1972 Zinfandel was a rich, flavorful wine with a deep red color.

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Trinchero was left with 550 gallons of light blush liquid. He fermented it into wine and sold it, with mild success, in the Sutter Home tasting room along Highway 29 in St. Helena.

But in 1975, the saignée juice pulled off the Zinfandel got “stuck.” During fermentation, the sugar in grapes turns to alcohol, but conversion stalled that year. No matter what he tried, Trinchero could not get his wine to complete fermentation. The resulting wine was sweeter than usual, with a 2 percent sugar level. Trinchero bottled it anyway.

The slightly pink wine was a hit. Consumers loved its sweetness. People who rarely drank wine were soon regular buyers of white Zinfandel. In 1980, Sutter Home produced more than 25,000 cases of the wine. By 1987, the winery was selling two million cases of white Zin, as it was affectionately called.

Soon, around 125 wineries around the state were selling their own versions of white Zinfandel, including some of the larger winemakers like E. & J. Gallo, Beringer, and Robert Mondavi.

The new popularity of the blush wine meant there was a rush to buy Zinfandel grapes. Demand soon outstripped supply. Prices soared. Zinfandel grapes, which had been selling for $100 a ton in the early 1980s, sold for $900 a ton a few years later. That was about $750 more a ton than other varietals like Carignane or Barbera.

To a number of grape growers in the Central Valley, the shortage of Zinfandel presented an opportunity—but not a legal one. Why not, some reasoned, pass off cheaper varietals as Zinfandel? After all, to the casual observer Barbera grapes looked much like Zinfandel grapes—big, red, and fat. How about going a step further, too, and selling French Colombard grapes as Sauvignon Blanc grapes or Thompson seedless as Chardonnay? Why not give it a try?

In the predawn darkness of the San Joaquin Valley, the men began to arrive slowly. Some came by car, others by truck. Engines rumbled, doors slammed, and soon the sounds of Spanish rang out across the hundreds of acres of grapevines that stretched far into the horizon. The men, most from Mexico and Central America, donned their heavy work gloves, picked up their shears and got to work.

Harvesting grapes is an art form of sorts, a balance of speed and delicacy. Temperatures in California’s vast Central Valley in late summer can easily reach 100 degrees by noon, so a worker has to pick quickly before the heat affects the fruit, but handle the grapes gently enough not to split their skins. The laborers that day worked at a rapid pace, clipping off the red, fat clusters and dropping the grapes into plastic crates at their feet. They moved from vine to vine and when the crates were full, they dumped the grapes into the back of a tractor-trailer narrow enough to navigate between the rows.

The pickers were probably too busy to notice the two men parked a few hundred feet down the road. The men had gotten to the vineyard even earlier than the workers and grabbed a spot under a large shade tree. It takes a long time to fill up a truck with twenty tons of grapes. The men in the American sedan had to blink off sleep and keep up a constant banter to stay alert over the course of the morning. They tried to be innocuous, too, by parking their car facing away from the vineyard. That let them monitor the harvest through the rearview mirror. But the men had gotten good at spying, their instincts honed after staking out a dozen vineyards over a six-week period. They had been working for almost a year to uncover one of the biggest wine frauds in California history, and the season of proof had finally arrived.

As the sun inched up higher into the sky, a truck loaded with glistening grapes pulled away from the vineyard. The two men watched it drive off, then did a U-turn, hoping the managers and workers in the vineyard didn’t notice them. The men followed the truck over back roads and watched it pull into a large winemaking facility. They noted the truck’s license plate, the time it left the vineyard, the time it arrived at the winery, and where the grapes came from. They had snared their prey.

The trucks laden with grapes had pulled into Delicato Vineyards in Manteca, about seventy miles east of San Francisco. In the late 1980s, Delicato was the largest maker of bulk white Zinfandel wine in California, producing it for Sutter Home and other wineries that sold it under their own labels. Delicato got many of its grapes from Michael Liccardi, a prominent wine broker from Stockton. Liccardi provided so many grapes that Delicato had given him unprecedented—and unsupervised—twenty four-hour access to their wine production facility. Liccardi even had his own office in the Delicato complex where he could schedule and oversee the grape deliveries.

With a seemingly bottomless market for Zinfandel grapes, Liccardi needed to figure out a way to increase his supply. So he recruited two grape growers, the brothers Frank and Nick Bavaro, to help with a scheme he concocted. The Bavaro brothers would harvest Carignane and Valdepena grapes and pass the thick, red-skinned grapes off as white Zinfandel grapes.

To make sure the falsification was not detected, the Bavaro brothers had their farmworkers pick grapes in the cool of the night and deliver them to Delicato anywhere from two a.m. to four a.m.— when no one but Liccardi was around. Over a few years, Liccardi managed to broker the sale of 4,900 tons of grapes valued at $3.1 million that weren’t what they purported to be. Those grapes produced 900,000 gallons of wine worth $18 million. The Bavaro brothers not only provided grapes to Delicato, but to unsuspecting wineries like Sebastiani Vineyards, Charles Krug Winery, and the Robert Mondavi winery.

Another grape grower who sought a shortcut was Fred Franzia, the nephew of Ernest Gallo and the founder of Bronco Wines (which would eventually launch the world’s best-selling brand, Charles Shaw, better known as Two-Buck Chuck). Franzia, a brash, loud man, thought most Napa Valley winemakers were snobs. Franzia disdained those “highfalutin” vintners because he believed good wine could be made inexpensively. He became particularly creative with the grapes he passed off as Zinfandel. His crew scattered leaves from Zinfandel vines on the top of other grape varieties to obscure their true origins. Franzia called this the “blessing of the loads,” a reference to the practice of blessing the harvest. Franzia also passed off Carigne and Grenache grapes, which brought in about $196 a ton in 1992, as Cabernet grapes, which commanded about $387 a ton.

The growers and winemakers obscured the varietals by falsifying the tags accompanying the loads of grapes to the winemaking facilities. When grapes are harvested, the grower is supposed to fill out a field tag with the name and address of the grape grower, the grape variety, the date and time they were picked, the name of the trucking company delivering the grapes, and the license number of the trucks. The truck driver takes the field tag to the winery, which then uses the information to prepare a certificate for the California Department of Food and Agriculture. The winery also uses the information from the tag to file reports to the Bureau of Alcohol, Tobacco, Firearms, and Explosives. Often, a state inspector is on site to examine the grapes. The men taking shortcuts began falsifying the field tags to read “Zinfandel” rather than the true names of the grapes.

The money came rolling in. Some brazen grape growers bragged about the scam openly in coffee shops and diners. Word of their exploits spread around the San Joaquin Valley’s tight-knit wine community. It angered a lot of grape growers who struggled to make an honest living. Some called up the California Department of Food and Agriculture to report the rumors. Others telephoned the ATF. Soon, the two agencies had agreed to work together to break open the counterfeit ring.

When the agents went into the wineries and asked to examine the field tags on file, they did not find anything suspicious. The paperwork was impeccable, disguising any evidence of fraud. So the agents dug up maps filed with the county that detailed what kind of grapes were grown in specific vineyards. Teams of agents staked out vineyards around the region to observe which grapes were picked and where they were delivered. At times, it was a twenty-four-hour job as the agents monitored the huge mechanical pickers that worked throughout the night, followed by the bands of laborers who arrived to pick at dawn. By following the grapes from the field to the winery and comparing what was picked to the description on the field tags, the agents were able to document that some growers were passing cheap grapes off as more expensive varietals.

Steven Lapham had been working at the U.S. Attorney’s office in Sacramento for four years when an ATF agent came in one cold day at the end of December in 1989 with a case he wanted to drop. It involved a grape scam and the agent didn’t think he had enough evidence to go forward. Besides, the ATF “did guns and drugs,” not wine. He needed Lapham’s okay to stop the pursuit.

The federal government at that time had a spotty history prosecuting wine fraud. The cases it did pursue were relatively minor in scope. In 1974, Almaden Winery had misrepresented what was inside 28,000 cases of wine it sold to airlines to put in those tiny screw-top wine bottles. The winery was fined $250,000—at that time the largest fine ever levied. In 1982, the bureau arrested a Sausalito man then living in New York, Louis A. Feliciano, who had commissioned wallpaper with the design of Château Mouton Rothschild labels. He cut out the labels and pasted them on forty cases of California wine.

As Lapham listened, he realized that the scale of the fraud the ATF agent was describing was huge. Lapham wasn’t someone who thought wine drinkers were rich and snobbish and deserved whatever they got. Nor did he think falsifying wine or switching out one type of grape for another was a minor matter. The California wine industry brought millions of dollars into the state economy each year and employed thousands of people. Lapham thought that if government didn’t clamp down hard on grape fraud, it would only grow in scope.

Lapham was a wine lover, and perhaps that perspective made him eager to pursue the case. It certainly helped him understand the seriousness of the fraud.

Lapham had a realization about wine in 1982 when he was thirty. He had been a casual wine drinker until then, never paying close attention to what he bought or what he drank. He was in Laguna Beach in southern California on Mother’s Day, visiting his closest friend and his parents. His friend’s father, a cardiac surgeon, brought a bottle of 1966 Château Lafite Rothschild to celebrate. Lapham still remembers his first taste of that famed wine. “It was like velvet. The tannins had all disappeared. It was flavorful, rich and full-bodied. I learned for the first time what good wine was supposed to taste like.” He vowed then and there to only drink good wine—not Château Lafite–level good—but good California Cabernet.

Lapham recruited a more enthusiastic ATF agent to oversee the grape fraud case. Eight months later, agents started to stake out grape fields all over the Central Valley. In the early 1990s, Lapham and California state prosecutors brought more than twenty civil and criminal lawsuits against Delicato, its president, Anthony Indelicato, the Bavaro brothers, Michael Licciardi, Fred Franzia, Bronco Wines, D. Papagni Fruit Co., and others, charging that they had fraudulently sold $26 million of grapes and wines that were not what they professed to be. All of those charged either pleaded guilty or were convicted. Bronco Wines agreed to pay a $2.5 million fine for misrepresenting 5,000 tons of Grenache and Colombard grapes as Zinfandel. They had passed off one million gallons of wine worth approximately $5 million as white Zinfandel when it was made from other grape varietals. Franzia paid a $500,000 fine and was forced to step away from the company’s presidency and the board for five years.

Lapham could have pushed to send Franzia to jail, as he did for the others convicted of fraud. But Franzia persuaded the prosecutor that the small town of Ceres, home to Bronco, would suffer financially if Franzia’s imprisonment triggered the company’s collapse. It was a concession that Lapham would regret years later as he watched Franzia and Bronco Wines grow in strength and financial stability while, it seemed to Lapham, skirting the edge of legality in other ways. Franzia’s conviction has not slowed down his ability to turn Bronco into the fourth largest wine company in the U.S. He now refuses to talk about the conviction in interviews. It weighs on his mind, though. In 2008, he asked President George W. Bush for a presidential pardon. One reason he wanted it was because he wanted to own a gun, which he couldn’t do as a convicted felon. His application was denied.