When father-and-son winery owners Jim and Bo Barrett start to argue, they climb into a homemade boxing ring built in the dirt near their rows of vines. At least, the Barretts as played by Bill Pullman and Chris Pine in Randall Miller’s Bottle Shock do; the actual owners of Napa’s Chateau Montelena bond a little differently.

“In real life they actually fly fish together,” Bottle Shock director and co-writer Miller admits. “But that’s in A River Runs Through It, so we didn’t do it.”

“It’s also not the right metaphor for their relationship,” points out Jody Savin, Miller’s wife, co-writer and producer.

“They spar with each other,” Miller continues. “So the boxing was a visual manifestation of that.”

That father/son relationship is what attracted Miller and Savin to the Barretts’ story. The pair was approached by the directors of the Sonoma Valley Film Festival with a long-dormant script by Ross Schwartz about the 1976 “Judgment of Paris” tasting. Usually intent on producing only their own material, the couple, who describe themselves as strictly Two-Buck-Chuck-variety drinkers prior to making the film, were reluctant to take on the project until they met with the Barretts.

“Jim is 81 now and Bo is 55,” says Miller, “and they’re incredibly colorful characters. So we decided to focus on the father/son story because we wanted to tell a universal story that didn’t just appeal to wine aficionados but was something that everybody could relate to.”

The wine story at the core of Bottle Shock details the moment at which the wine business changed, turning the Napa Valley from a farm town to a tourist mecca. The hurdle for a filmmaker, then, is to somehow conjure 1976 Napa from its modern counterpart. “Luckily,” Miller says, “in the vineyards you’re looking at vines. The landscape hasn’t changed and it won’t change after we’re gone.”

As the movie premièred at Chateau Montelena last week, however, the story suddenly came full circle, as the news broke that the Barretts had sold the operation to Bordeaux winery Cos d’Estournel. “It’s an interesting coincidence,” Miller says. “But we never really intended to make a ‘rah-rah, U.S., down with the French’ movie. It’s really about the democratization of the wine business.”

“And also about the human spirit and the pursuit of an artistic form,” interjects Savin.

“The irony,” Miller concludes, “is that the French couldn’t beat ’em, so they bought ’em.”

BOTTLE SHOCK opens this Friday at the Osio Cinemas.