Most of her time in the recording booth, Kerri Miller has a stolid working face, her chin resting in her hand, eyes focused on some point in the distance past the microphone, or down at her notes. That changes when the discussion turns racy.

On a recent morning in the studio, her guest Rachel Hills, author of "The Sex Myth," mentioned a viral image of a ham sandwich that had been made to look like a female sex organ. Miller sat up, and slipped into a resistant, blushing grin.

Masturbation, virginity and a euphemistic ham sandwich are not the usual talk radio fare. But Miller, Minnesota Public Radio's midmorning news host, is lending her familiar voice to a topic that some loyal listeners might find shocking: sex.

Launched earlier this summer, "SmartSex," a podcast, is a passion project Miller hosts outside of her MPR duties. With expert interviews and advice, "SmartSex" aims to offer women frank discussions on sex and sexuality — a task that is easier said than done.

"The main thing women need when talking about sex and sexuality is a sense of permission," said Emily Nagoski, author of the bestselling book on the science of sex, "Come As You Are."

"Women get taught from really early on in our lives that there is a wall between us and our own sexuality, or that there is some hurdle we have to overcome before we are allowed to experience sexual pleasure and to talk about our sexuality," said Nagoski, who was a guest at "SmartSex's" first live event in Minneapolis.

A forum like the podcast, where women can talk openly about their sex lives, cuts through that wall, Nagoski said, "and says you have permission to not know everything yet."

Early guests have included Peggy Orenstein, author of "Girls and Sex," in a discussion on pornography, and Jennifer Pritchett, co-founder of Minneapolis sex toy store Smitten Kitten. With a number of authors in the mix, the show resembles something of a sexy Talking Volumes — an author series sponsored by MPR and the Star Tribune, which Miller also hosts.

"SmartSex" is a departure from the news, politics and literature beats that Miller commands on MPR. And it all started because of a sex toy.

Miller and Teresa McFarland, who have been friends for 20 years, had just gone hiking together when Miller mustered up the courage to bring up something intimate — a type of sex toy she likes. It was something she'd never discussed before with any of her longtime pals.

"You watch your friends for their reaction," said Miller, 56. "Is the door open? Is she going to slam it?"

Instead, McFarland, 50, who is in public relations, listened, offered no judgment, and wondered aloud why she and her friends didn't talk about sex more.

"This conversation was so enlightened, so smart, and I felt like that would be something on Kerri's show," McFarland said. "Of course, it was probably not the content you'd have on Kerri's show."

They bandied about an idea to replicate the conversation for other women, and on another hiking trip, came up with the plans for a self-funded podcast and live "SmartSex" salons to be held around the country.

Since its launch June 3, "SmartSex" has been downloaded on iTunes more than 4,000 times. That's a fraction of the audience for Miller's MPR News podcast, but the fledgling show's online reach at SmartSex.org is growing every day.

Miller did not approach MPR about broadcasting the program because she wasn't sure how explicit the content would be. Since the podcast has begun, however, "the door might be cracked open a little bit to share some content" with MPR, Miller said. As for MPR, "We're watching it," said Nancy Cassutt, executive director of MPR news and programming. "If this is something that makes sense [for us], we would have a discussion about it."

Cassutt said Miller's side project doesn't pose a conflict with her news duties.

"Kerri is a big talent for us and has two hours of our audience every day, so I want to keep her happy and engaged," Cassutt said. "People are creative souls who work here and they like to explore things outside of work, and this is something we completely support for her."

Intimate and open

That first conversation between Miller and McFarland was the model for the show's approach — a judgment-free zone to talk about life's most intimate details. To that effect, they created a segment called "Never Afraid to Ask," which has women calling in with questions and Miller asking her interview subjects for answers.

At the latest recording session, a 41-year-old woman called in and remarked that her husband was shocked that she would be speaking with Miller, whom he recognized from her previous job as a political reporter for KARE-11. Then she asked about threesomes.

The surprise that such an authoritative news voice is taking questions about topics like threesomes comes up again and again for people who have encountered the project. But it's also what makes the podcast so effective, they say.

"Kerri as the voice of this gives it huge credibility," said McFarland.

"What's interesting is that it's stuff that would not make it on the air on public radio," said Chris Heagle, the studio manager for On Being/Krista Tippett Public Productions, where "SmartSex" is recorded. "It's really an extension of what Kerri does on her show, but it's a different Kerri Miller that's interested in what they're talking about."

Miller admitted that some listeners "will feel a dissonance."

Katherine Kersten is one of them. "The smooth, poised, professional voice of a successful woman of some years — it's jarring to hear her tittering about sex toys," said the conservative writer and senior policy fellow at the Center of the American Experiment.

Kersten criticized the podcast for promoting pleasure above partnership. "This is a very narrow, stunted view of human sexuality," she said. "It's completely missing the beauty and the artistry and the glory of an adult sexual relationship founded on the devotion to another human being and the creation of life."

But Miller and McFarland say the program's purpose is to unify the many facets of women by acknowledging that they can be considered smart and professional and they also can talk openly about sexual pleasure.

"There doesn't have to be this split between 'This is who I am as I present to the world, and this is what I do that I'm kind of ashamed of,' " Miller said. "Get rid of the shame."

That's something even Miller has to work at.

A recent interview with a blogger got pretty risqué when it veered into the topic of "masturbation circles."

"I'm in the studio alone, and I had this moment of a flush coming up my body, thinking, 'This is Kerri Miller, sitting here talking about masturbation circles,' " Miller recalled. "And then I said to myself, 'Grow up.' "

Sharyn Jackson • 612-673-4853

@SharynJackson