For centuries, rice-wine expertise was limited to men. Now, women are connoisseurs – many right here.

If you want to know anything about the sake on Nancy Cushman’s well-edited list at O Ya, be prepared to give your undivided attention.

 Cushman, co-owner of the Japanese restaurant in the Leather District, describes the qualities of each sake the way an art history professor might rhapsodize about the different phases of Picasso’s life. Meibo Midnight Moon has melon and apple notes. Chikurin Hou Hou Shu Sparkling Sake is more yeasty. Mukune is well suited for someone with a dry palate.

While Cushman’s husband, Tim, helms the kitchen, she oversees the sake list, which includes premium brands that can fetch up to $89 for a 300-milliliter (or just over 10-ounce) bottle. With the sake world booming, producing an array of styles from breweries throughout Japan, it makes perfect sense that Cushman dubs herself a sake “sommelier,” a term usually applied to restaurant wine experts.

“It’s as fascinating and complex as the wine world,” Cushman says, “but there are still relatively few people who know that.”

Nor do many know that only about 30 years ago, women were not even permitted in sake breweries, a fact that for centuries made the sake world quite the boys club. But that’s changed. And in Boston’s thriving dining scene, a handful of women have made it their business to become connoisseurs of sake, educating curious diners about its finer points.

Leah Ikeda, who oversees the wine and sake program at Pho Republique, the kitschy South east Asian outpost in the South End, considers sake “one of the most diverse and complicated liquors in the world.” When Ikeda started learning about it, she’d go to tastings where she’d be one of just a few women – if not the only one.

The rest were men in suits, not all of whom were eager to share their knowledge. But instead of finding it intimidating, it piqued her curiosity. Ikeda, who has a penchant for obi-style belts, eccentric headwear, and chunky metal jewelry, would not be deterred.

“Ever since I was a kid,” she said, “I never liked people saying no to me.”

The fraternal order of sake brewing goes back for centuries to its earliest days of production. The beverage is commonly referred to as rice wine but is actually brewed from a rice-based mash of polished grains, much like beer is brewed from a mash of malted barley and other grains. The more the rice grain is polished, the more refined (read: expensive) the sake will be.

The brewing process, which is labor intensive, became a way for rice farmers throughout Japan to make a living in the colder winter season while their crops were dormant. Historically, techniques and recipes in each brewery, or kura, ware passed on by the master brewer, or toji, to his sons. It was considered a sign of manhood when a Japanese boy made a pilgrimage to a nearby brewery to apprentice.

But the pressures of the modern world have turned the tradition upside down. More young people choosing city life over the farm, combined with the skyrocketing popularity of sake in the West, meant that suddenly women were welcome to study the art of brewing.

“There’s a necessity of having more people experienced with the sake brewing world. If an older brother of an owner of a company decides to go off and do something else, a daughter would have to learn how to brew and could become a master brewer,” explains John Gauntner, an American based in Japan who’s recognized as one of the world’s leading sake experts. He conducts professional training around the globe and has authored several books on the beverage. “Traditionally people leave their homes and work in a brewery for at least six months, but there’s been a decline in that in Japan for a while. Breweries adapt by hiring local people – including women. The doors are opening more. It’s not as insulated.”

The first female sake brewer was licensed in 1976 at Ichishima, a brewery in northwestern Japan. Still, it’s not unusual to see gender divisions in otherculinary professions still entrenched today. Gauntner points out the rarity of female sushi chefs. It stems in part, he explains, from an ancient belief that women shouldn’t handle sushi because their hands are too warm and that will ruin the fish. It’s an idea that Ikeda deems “wildly offensive.” She also mentions the gender discrepancy when talking about the sake world.

“The notion that even my touch would devalue something is reason enough to encourage me to pursue this study and get into it in a way anyone should recognize all women can,” she says.

But as interesting as sake is, the big draw for Ikeda is the message in every bottle.

“Sake lends itself to stories more so than anything I’ve ever encountered,” Ikeda said. “Breweries hire artists to design beautiful rice paper labels and so many brands of sake have names attached to local lore.

“The people most interested in it are adventurous and tend to be more interested in an overall experience. And women tend to remember the stories and how these artisanal items represent people and people’s culture more often than men do.”

Jenny Chow is a co-owner with her husband, Jack Huang, of Back Bay’s sleek sushi eatery Douzo. She’s in charge of its sake program. Having grown up in Taiwan, sake isn’t just a drink to her, it’s a lifestyle, one she asserts “does the body good.”

And not just as a beverage. Koji acid in the rice used to make sake has restorative qualities for the skin. Several Japanese skincare lines are made with mixtures of nutrient-rich amino acids extracted from the rice during fermentation. Sake spas are not unheard-of.

“You put a cup of sake into hot water and just jump in,” Chow says. “It relaxes you and makes skin incredibly soft. It’s a spa treatment in Japan.”

Gauntner says in the past five years, as attendance at his seminars has spiked, the demographic has shifted as well, with more women learning the ins and outs of brewing. That shift is passed on to the curious public.

“For a long time mostly older men were drinking [sake],” he said. “The demographic of who’s buying premium sake is broadening to include women in their late twenties to early forties. And there’s just an appreciation for premium sake. It’s not that labels are designed to appeal to women.”