(NYTimes) - About once a month since the Napa Valley Wine Train began chugging through California’s wine country in 1989, the sound of clinking stemware has been accompanied by the spectacle of passengers being removed from the train.

Usually, the passengers are intoxicated and have become belligerent or unruly, said Anthony Giaccio, the company’s president. In the most egregious cases, the company had to remove a drunken man who tried to climb atop one of the locomotives, and a bickering couple after a verbal dispute became physical, he said.

The man, he said, “probably saw too many Westerns.” As for the couple: “She wasn’t happy with him and he ended up with a fork in his skin. That’s probably one of the wildest stories I’ve heard over the years.”

The process seemed to work until last month, when 11 women in a book club were booted from the wine train for laughing too loud. Their treatment led to a social media debate that focused on a single question: How loud should a trip to wine country be?

“If I can’t be loud while imbibing wine with a group of friends, then what’s the point?” Vicente J. Godfrey wrote in a one-star review he left on the Napa Valley Wine Train’s Facebook page amid a social media firestorm over the incident.

Josh Stewart, leaving a five-star review, took a different view: “I don’t think it’s appropriate for anyone to be loud on a wine train. If this was a liquor train or a beer festival, I would understand.”

Although the company has apologized to the women and offered to have them return for a trip in a private car, it also received hundreds of negative reviews on Facebook and Yelp. The book club, many of whose members are black, has retained a lawyer, Waukeen McCoy of San Francisco, who said they are considering legal options including a racial discrimination lawsuit. He said his clients want the wine train’s employees to receive diversity and sensitivity training in hopes that standards for conduct will be applied fairly across racial and ethnic lines. “They just don’t want this to happen to anyone else,” he said.

The incident cast a spotlight on a recurring challenge faced by wineries and tour operators: how to police noise levels without overdoing it.

It is a conundrum that curators of the wine-tasting experience have increasingly grappled with, as an industry boom that stretches back more than 20 years draws large crowds to long-established wine regions in California and New York, as well as budding production centers in northern Michigan, Virginia and elsewhere. The influx has forced wineries and tour operators to seek ways to balance the quality of a sampling session with the appropriate amount of fun.