Among the hundreds of winetasters Saturday at the Timber Crest Farms collective in Dry Creek Valley's were many who looked as if they might be en route to a campus party instead of a classic Wine Country event.

A hand-lettered tribute to the Kappa Delta Zeta sorority on the rear window of a parked SUV hinted at the youthful flavor of the crowd.

Several large parties gathered on the hill above the tasting room complex for the afternoon — their wristbands and glasses good for wines from all nine wineries at the site.

"We came here because there's a lot of wineries here," said 21-year-old Sonoma State student Caitlin Lavezzo, who recruited about 15 friends to share a limousine for the day.

"This is the party spot, really," said Bev Gill, hospitality director for Papapietro Perry Winery, looking out at a large asphalt area edged by tasting rooms and swarming with people. "This is really the epicenter."

Organizers said 19,000 people paid advance admission for the 33rd Annual Barrel Tasting, a six-day affair that runs Friday-through-Sunday this weekend and next.

They expected that an additional 6,000 to 8,000 people would pay same-day admission for the chance to taste the fruits of up to 136 northern Sonoma County wine producers.

Many visitors are repeat customers from as far as the East Coast coming for the opportunity to taste low-production wines that aren't available on the mass market, said Jim Forchini, owner of Forchini Winery and Vineyard, as tasters filled the cellar at his family winery off Dry Creek Road.

Others are finally getting around to checking out wineries they've wanted to visit but haven't yet, said cashier Kim Wilson.

Most wineries hope the event results in sales of both finished wines and futures — the final result of what's still fermenting in the barrels and available for tasting this weekend and next.

But, as many in and on the periphery of the local wine industry have observed in recent years, there is a large proportion of younger tasters attending the event each year — the so-called Millennials — attracted by the $20 admission price that's good for up to three days of fine wine tasting with no commitment to buy.

Instances of rowdiness and drunken behavior have soured the event for some and prompted efforts by the organizing agency, Wine Road Northern Sonoma County, to reach out to would-be tasters with a message of moderation.

Wine Road had signs printed to remind tasters to leave their beer and distilled beverages at home. The organization also paid for two CHP officers to be added to the weekend roster specifically to patrol the Dry Creek, Alexander and Russian River valleys.

Healdsburg Police Chief Kevin Burke said he had two extra officers on duty Saturday to patrol the downtown plaza, where tasting rooms were participating in the weekend event.

Burke, who is new to the city, said he'd heard the barrel-tasting weekend sometimes turns rowdy, but on Saturday afternoon things looked "really calm."

"Everybody is having a really good time," he said.

San Francisco resident Jeff Cole, 26, who came with Lavezzo's group less for the wines than "for a day out," said he could see how some folks might get out of hand.

But other young tasters praised the event, saying it provides exposure to different wines and an affordable opportunity to learn from winery staffs.

"The lower prices are a nice way to help new people, to give them an interest in wine," Livermore resident Jacob Anderson, 27, said.

"We started out tasting when we were 21. We grew into wine lovers," said 26-year-old San Francisco resident Matt Van Horn, now a member of three wine clubs and a frequent taster around northern California.

"We always felt like it was disrespectful to go and do all this winetasting without buying anything," said his girlfriend, Lauren Fishman, who was celebrating her 27th birthday.

The wineries didn't make much off them in the early days, but "now that we have more money, we buy a lot," she said.