Anyone out for dinner and drinks on a weekend in Portland – or touring its breweries or cruising Casco Bay – has come to recognize the gangs of high-spirited, well-lubricated and sometimes raucous young men or women taking on the town.

Elaborate, dayslong parties for brides- and grooms-to-be have become the norm for affluent millennials across the country, and that means groups of a dozen or more revelers descend on cities big and small almost every weekend, spending freely on rooms, food, drinks and entertainment. Portland, with its much-hyped restaurant, bar and brewery scene, is now officially on the pre-wedding party map.

Lauren Lessard’s party is typical. Lessard, 26, and her seven friends stayed in a house rented through Airbnb. They spent a sunny Saturday afternoon adorned in matching T-shirts, sunglasses and hair ties, sipping hard seltzer on a Casco Bay party boat whose journey was punctuated with peals of laughter.

Lessard grew up in Arundel but went to school and lives near Boston. Her party, ahead of her November wedding, was an excuse to experience a city she doesn’t recognize anymore.

“This Portland isn’t the Portland I grew up with,” Lessard said.

That afternoon was spent touring the Old Port. At night they would change into evening wear and hit the town – a big dinner at Walter’s, cocktails at the Top of the East and Blyth & Burrows. On Sunday morning they’d get a high-end brunch at Chaval.

“Basically, our plan was to eat and drink our way through Portland,” Lessard said.

Than Mulkern, captain of the Maine BayCycle boat, ties up the pedal-powered vessel after Lauren Lessard’s floating bachelorette party returns to Commercial Street in Portland after a 90-minute charter last month. Bachelorette parties are a big part of the pedal pub company’s business.

Once a humble night out with some friends shortly before wedding day, bachelor and bachelorette parties have transformed into destination events.

“It became not just about one night out but a whole weekend,” said Beth Montemurro, a professor of sociology at Penn State and author of “Something Old, Something Bold: Bridal Showers and Bachelorette Parties.”

Lessard and her friends tick off the reasons why: Everything about weddings has become more elaborate and expensive; friends live all over the country and a weekend trip is the only way to get people together; social pressure to plan and attend.

“Everything tied to a wedding is more extravagant than it was 20 years ago,” Lessard said. “Parties like this are expected now.”

‘TIPSY SHOPPING’ IS BIG BUSINESS

There’s no accurate estimate of how many bachelor and bachelorette parties come to Portland, or their economic impact. Visit Portland, the city’s tourism agency, thinks it is a small, but growing, part of the overall tourism economy. Last year Visit Portland’s website specifically for bachelor and bachelorette parties had 3,111 unique visitors, an 8 percent increase from the year before.

But for some businesses, pre-wedding events are now guaranteed customers.

“One Saturday last summer, in July, we had six reservations back to back to back to back, from noon to 5:30. There were five additional groups that walked in,” said Rebekah Messer, events manager for Cellardoor Winery, which has a tasting room in Thompson’s Point.

About 80 percent of the private bookings at the tasting room are bachelorette parties – eight to 10 a week on average, Messer guessed.

Matching outfits are common, Messer said. So are tiaras and sashes for the bride-to-be. A stretch limo isn’t unusual.

Most groups are around a dozen women. At $50 for the private rental and $8 tasting per person, an hourlong private session runs about $150. That doesn’t include another $8 glass of wine or two, plus maybe a bottle, T-shirt or wine bag to take home.

“We call it tipsy shopping,” Messer joked. Better than the cash flow, however, is the exposure Cellardoor gets, especially from posts on Instagram, the wildly popular photo-sharing app.

“It definitely contributes to the bottom line, but it is amazing word of mouth and social media,” she said.

The phenomenon hasn’t surprised Neil Kinner, but the magnitude has. Kinner moved from Portland, Oregon, back to its East Coast namesake a few years ago and started Maine BayCycle, a slow-moving party boat powered by two rows of bicycle pedals. It’s the closest approximation to popular pedal pubs – an on-street version – that have popped up across the country in recent years.

“I knew bachelorette parties were going to be a big part of it from the get-go,” Kinner said.

He wasn’t wrong. On some weekends, every one of his five daily tours – at $450 for a 90-minute private charter – is a bachelorette party, about half of the 1,800 people he had last year.

“Bachelorette parties seek out that pedal pub stuff,” he said. “It’s the first thing they look for.”

BOOMING BREW SCENE HELPS

As a destination, Portland has a lot going for it, Kinner added. It’s small, so groups can get around easily without getting disoriented or split up, and transportation is cheap. There’s plenty to see and do, a hip vibe, and a huge food and booze scene.

Maine’s booming craft brew industry is part of the draw for pre-wedding parties, said Don Littlefield, general manager of the Maine Brew Bus, which offers tours of Portland-area breweries. Roughly 70 percent of the company’s group sales are bachelorette and bachelor parties.

From left, Jared Pedjoe, Joe Tomaski and Christina Tomaski sample beer at Austin Street Brewery during Jared and Joe’s bachelor party weekend recently. The couple came up from Massachusetts for their bachelor weekend getaway that Joe’s sister, Christina, planned and friends flew in from around the country.

The big parties are usually people “mildly affiliated with Maine or people who have no affiliation with Maine, but have heard about the scene we have here, the concentration of food and drink and nighttime entertainment,” Littlefield said.

Portland’s tourism profile already skews thirsty, hungry and young. A third of overnight visitors to the Portland area were younger than 35 years old, according to a 2017 survey commissioned by the Maine Office of Tourism. More than half the tourists surveyed said food, beverage and culinary activities were the top reason they came to the city, and 48 percent reported visiting a craft brewery.

Some weekends, Flatbread Company, a pizza place on Commercial Street, serves 10 bachelorette or bachelor parties a night, and can have four groups dining at once, said manager Tom Cancelliere.

“We have definitely seen an increase in business – we love having them,” he said. The restaurant is right next to the ferry terminal and Maine BayCycle.

Young groups typically spend big, but can be challenging, Cancelliere said. Guests try to sneak drinks in the bathroom, and he’s had to tell groups to put away phallic-shaped straws or cut some people off if they’ve had one too many.

“They are usually kind of rowdy compared to families and couples,” he said. “We don’t usually get the 21- to 35-year-olds coming in with more than their fair share of alcohol.”

SOCIAL MEDIA AND SPENDING

Andrew Lewis, 24, a University of Connecticut graduate student, took seven months to plan a bachelor party for his identical twin, Matthew. In early May, he led a group of 15 men – from Boston, Connecticut, New York City, Philadelphia and Savannah – to a house in Kennebunkport for the weekend.

“My brother said he wanted to drink beer and play golf and the places we could find the most golf courses and breweries per capita was Portland,” Lewis said.

The plan for one night was a massive backyard barbecue. Another day was filled with a trip to Allagash Brewing, a Maine Brew Bus tour and dinner at Scales, an upscale seafood restaurant on the Portland waterfront.

“I think the reason he chose Portland is there is a lot to do in this area,” Lewis said. “It is quiet, nice, secluded; we all live busy lives but to be in a cool city with lots to do is a really nice change of pace.”

Many groups have a similar busy schedule, giving partiers plenty of time to splash money around.

The average destination party guest spends $537 just on travel, accommodation and gifts, according to a 2018 survey from wedding website The Knot. The per-guest cost is more than half what people spend to attend an out-of-town wedding itself.

“This is the only time in your life you can justify asking all your closest friends to celebrate with you in a really cool destination,” said Maggie Seaver, assistant digital editor for The Knot.

The phenomenon intrigues Montemurro, of Penn State. Bachelorette parties, as a term, first surfaced in the 1980s, she said. As soon as the idea caught on, the nightlife industry grabbed and expanded it, creating night-out packages, and then trips to Las Vegas and other big cities.

Social media seems to be partly driving the enduring popularity of elaborate bachelor and bachelorette weekends.

Seaver said there is a lot of pressure to showcase your experiences to the world. Montemurro agrees.

“The posting, the documenting of it is really significant,” she said. “It shows people that other people do it; it shows you that it can or should be done.”

And that provides an extra boon to the businesses that cater to these groups.

Nashville, Tennessee, has become the newest hot spot for the bachelorette party industry, an unexpected development that spread through word-of-mouth and Instagram accounts. Groups come by the dozens every weekend and are a common sight on pedal pubs and the city’s famous honky-tonk bars.

“They stay in nice hotels, have at least one nice dinner, go to a spa, pampering, and then they party pretty hard,” said Butch Spyridon, CEO of the Nashville Convention & Visitors Corp.

Portland hasn’t gotten to Nashville’s level and doesn’t have the Southern city’s size or draw of daily free live music. But the trend is here, and with Portland’s mix of food and fun, there’s no sign it is slowing down – just ask Spyridon.

“I’m surprised both by the magnitude and the duration the phenomenon has run,” he said.

“The volume of spending, the duration of stay, it is all somewhat surprising.”