After three decades, the annual Wine Road Barrel Tasting is more popular than ever, but this year it revealed a simmering generational feud. The dispute pits aging Baby Boomers, who have long supported the event, against younger wine drinkers who taste with, shall we say, more gusto.

This month, the two-weekend event drew thousands of people who cruised the back roads of Sonoma County, with more than 100 wineries open for tastings. The atmosphere is generally festive, with food, wine and entertainment offered at most tasting rooms. But this year more people have complained about the party atmosphere at a few wineries and particularly around Healdsburg Plaza, the hub of several tasting rooms.

Many see it as a generational divide. Baby Boomers, who recall the event as a more serious tasting, have been increasingly put off by some Millennial wine lovers - ages 22 to 31 ? who see it as a festive day of wine drinking.

As Timothy Nordvedt of Healdsburg?s Bella Vineyards put it: ?I believe that we might all agree that Coors Light is the official beer of barrel tasting weekend as it was the most common can coming up to the winery from the parking lot in the hands of a 20-something taster. Many tasting glasses were offered for filling with a sudsy residue already present."

Beth Costa, executive director of Wine Road, the event?s sponsoring organization, said the problem drinking isn?t at the wineries, where tasting is limited, but typically is a result of serious drinking on buses and in limos between stops. ?It is a serious problem and one we will continue to try to solve.?

Costa expects the Millennials to be regulars at this event because of the affordable $30 ticket price and because it caters to the curious. ?It provides a relaxed setting to talk with winemakers and ask questions,? she said. "So it can be very educational, but not in the way a formal wine-tasting class would be conducted."

Barrel tasting is a sneak preview of wine that won't be available for another year or two. Many wineries sell so-called futures on their barrel samples, offering discounted prices to encourage purchases now.

While the event reeled in a younger crowd this year, organizers said they didn't set out to target a particular age group. However, this was the first year the Wine Road committed a larger percentage of its advertising to new online sources rather than print publications.

"The Millennials are so well connected that if they are interested in some particular event such as barrel tasting, they can tell thousands of their friends with one click of the mouse," Costa said. "They're the generation that is online. They Twitter, FaceBook and MySpace their weekend plans. It's all you read about these days, the Millennials. They're sociable, well-educated, open-minded, and influential."

Costa said the wine industry needs to embrace the younger enthusiasts. "They are the wine drinkers of tomorrow," she said. "They are welcome, but they need to be respectful and cognizant that they are sampling wine in order to make smart buying choices. It's not a free-for-all."

And yet a free-for-all of sorts is what some say they experienced. In fact, one couple from Columbus, Ohio went back to the Midwest in a huff. Mary Marucco, 50, said she and her husband Tony, 46, won't ever take part in the event again because of the antics of the younger crowd.

"This year there were lots of buses and there were a lot of mid-20-year olds misbehaving," Marucco said. "We've dealt with buses before, but it was just this attitude that 'I've paid my money and I'll drink as much as I want to.'"

Marucco said one group was wearing St. Patrick's Day clothing and "they looked like they should have been at a microbrewery...It was just really irritating."

What's Costa's response to this couple? "Sometimes it's just a matter of being in the wrong place at the wrong time," she said. "This couple may have seen the one and only disruptive group that particular winery saw over two weekends."

Indeed, there were no problems reported by California Wine Tours, according to Mimi Gatens. The company, which has offices in Napa and Sonoma, had a total of 42 limos and 33 buses transporting tasters during the event's two weekend run. "We didn't get any comments back from our drivers, but they're good at controlling inappropriate behavior or taming it."

But Jennifer Buffo of Pure Luxury Transportation based in Petaluma, said she heard stories of other limos and buses encountering difficulties, even though her fleet of 40 limos and 40 buses involved in the event did not. "I heard it was much more crazy in the Dry Creek area than Alexander Valley ... I heard some people were kicked out of wineries because of their behavior."

Zack Zimmerman, a 24-year old student at Sonoma State, said none of this behavior surprises him. "I've heard people (ages 21 to 24) say: 'Let's go to a wine tasting and get plastered.' One problem is people treat wine like they do liquor at a bar."

Zimmerman said the biggest challenge for marketers is to find the group of younger wine lovers who can appreciate and respect wine and the passion that's behind it.

Bruce Cousins, who co-owns Healdsburg's Armida Winery, agrees courting a younger market is tricky. He said that on the second Saturday of the tasting, Armida had seven to 10 limos and buses arrive within the first 20 minutes of opening.

"It was just an onslaught," he said. "Most people in their 20s ... the younger kids are just out to have fun. For wineries, how can we stop it or change it? Where to we draw the line without shooting ourselves in the foot?"