Lauren Laverne is not yet wearing a black dress with blue four-inch heels. She is not made up.

Her hair is still undone. She looks nothing like she does on television. She is on a chair in the make-up room of BBC Scotland's Glasgow headquarters and will shortly present an episode of The Culture Show, which she co-hosts with the film critic Mark Kermode.

The show's Scottish producer, when he pops in, is greeted with Laverne's warm Sunderland tones, despite trying to hurry her along. "If it looks crap we can wash it off," says Laverne to the stylist, who is about to apply some coral eyeshadow.

Today marks the first time since her son Fergus was born last year that she will spend the night away from him. Doing her job, by comparison, is child's play.

"I don't ever get nervous because I enjoy what I do," she says. "I mean, it's just a camera, they're just lights. It would be like getting nervous about a hairdryer because they're just electrical appliances. I'd feel worried if I had to cook a quiche or something, but definitely not making a TV show."

Around half of the current series of The Culture Show will be filmed in Glasgow with Scottish audiences, alternating with shows recorded in London, where Laverne lives with her husband, Graeme Fisher. Now airing in the "quite jazzy time slot" of Tuesday evenings at 10pm – the traditional preserve of shows like Never Mind The Buzzcocks and Jools Holland – the programme is repeated with extended footage on Friday evenings.

Part of the show's appeal is the breezy counterbalance Laverne provides to Mark Kermode's bewailing of certain aspects of popular culture, particularly film. Her down-to-Earthness is matched by a genuine enthusiasm and her peculiar, sometimes hilarious, way with words.

Having the current series launch in the same week as her new BBC 6 Music programme was, she says, "a new leaf moment"; she describes Transmission (the E4 music show she hosts with the toothy but tender Steve Jones) as "straightforward, balls-to-the-wall, rock-and-roll-all-night-party-action". On The Culture Show's website, the public is asked to define what "culture" actually means, but few answers are as interesting as Laverne's.

"It's all the things we aren't that tell us what we are," she says. "Whether it's a painting, a building, or a song, it's those things that tell us who we are better than we could ever say in words."

The show, she says, suits her more than any other she has done, although she could never have predicted being chosen for it. She started, aged 15, as the singer, songwriter and guitarist of 1990s teenage punk outfit Kenickie, who scored four T op 40 hits and released two albums. She invented the surname Laverne while mocking up a poster for the band's first gig because she liked its "pleasingly alliterative" sound (her real surname is the far less alliterative Gofton).

Her brother Pete, who played drums in Kenickie, was renamed Johnny X. Relocating at the height of their popularity from their hometown of Sunderland to a flat in Camden left Laverne feeling "intense claustrophobia and depression". The band consequently split up at the end of a set at London Astoria in 1998 with Laverne's last words:

"We were Kenickie ... a bunch of fuckwits." I mention that I have read somewhere that Laverne's landlord in Camden was Shakin' Stevens, who is due to play Glastonbury later this month.

"No, that's just a rumour," she says, "but he did stay just round the corner. His house didn't have a green door but it was a sort of eco-house, so I suppose they were green doors in a way. But I'm very much looking forward to some hot Shaky action at Glastonbury this year."

Is she a fan?

"Who isn't?"

I never was.

"Oh, come on Snow is falling (click, click), all around us (click, click)."

The stylist laughs, and then tries to pull Laverne's head back into check. Unfortunately, every time she does this Laverne's eyes are drawn back to the mirror, which allows only side-glances in my direction. Unfortunate because, having watched Laverne on television for years, I know her strength is her eyes.

Her default on-television sitting position – one leg crossed over another, her hands cupped around the raised knee - no doubt inspires confidence in her interviewees, but it's her eyes that draw them in.

"Most interviewers don't even listen when they're interviewing someone," she says. "They formulate questions around an expected set of answers rather than having a conversation. I always aim to listen and get the best out of people." She loves working live because "it always feels like everything's just about to completely fuck up and that's quite an exciting sensation".

One close shave came with The Fall's notorious frontman Mark E Smith, who Laverne interviewed live on Transmission, and who struggled to find comprehensible one-word answers. Another, less threatening interview was with a sleep-and serotonin-deprived Pete Doherty at the start of his tabloid demise.

"He was absolutely mangled," says Laverne. "It was just four days after he got together with Kate Moss, during which they hadn't been to sleep." But even when she can, she never pushes for big confessions. "I think it's slightly creepy to try and get exclusives or get dirt on someone. It's great if they want to say something, but I'm not there trying to trick them in any way."

Laverne's accidental path into media began with guest appearances on panel shows such as Have I Got News For You and Never Mind The Buzzcocks, on which she famously described the Spice Girls as "Tory scum". In the decade since, she has presented on television and radio, which has included regular slots at Glastonbury and T In The Park.

At 30, she is young, striking and gobby but as comfortable discussing Nietzsche as she is her love of second-hand bookshops; as excited by the prospect of interviewing Fight Club author Chuck Palahniuk as she was championing Klaxons to their Mercury Music Prize last year.

In another life, she may not have turned down an offer to read mediaeval studies at Durham University. Ed Simons from the Chemical Brothers has given her a few lessons on this subject in passing, but she remains largely self-taught.

"My dad's an academic and my mum's a retired college manager," she says. "Growing up in a house like that, you learn that education is not about reading the right books or memorising stuff – it's about being passionate and engaged. Degrees are important and wonderful and a great achievement for people, but I think that the great success comes from following things that you genuinely love and are fascinated by.

"I didn't go to art school. I probably couldn't tell you who made a particular sculpture unless it was something completely obvious, like an Anish Kapoor reflective, shiny thing, but I don't think that matters because the things that I love I know all about."

Chief among those is music. Her father lectures on the sociology of pop music at Durham University and once played with the musicians who later formed Roxy Music. His knowledge of the subject dwarfs Laverne's, but her upbringing affected her profoundly. "I've been obsessed by music since I was 13, or younger," she says.

"That's my little world of geekery and everything else spreads off from that. You can't love music and not be interested in fashion or style or books, because they inform the thing that your life is constructed around and made of."

She assumes, without a trace of self-pity, that she has been "slagged off roundly" in some quarters since taking the reigns of The Culture Show in 2006, but avoids looking for confirmation because "it's the road to narcissistic insanity. People don't have to like me," she says.

"If I was to be down on someone for having an opinion, I'd have to have none myself – and I definitely do, so I respect that. It's never the best day of your life when someone says, You're really shit', but that's just part of the job."

She refers to Terry Wogan and Jonathan Ross as "the daddies" of British broadcasting and admires them for possessing "charm and elegance in spades". Her delivery, as host of XFM's breakfast show, was more like theirs than that of her Zoo format contemporaries such as Radio 1's Chris Moyles.

On getting the job in 2005, the general expectation was that she would be another Sara Cox or Zoë Ball – a beer-swilling ladette, as happy to burp into the microphone as to deliver a set of bawdy one-liners.

Thankfully, she was like neither. She has opinions but is not rude with them. She has pluck but is not pushy. She gets exposure but doesn't hog the limelight. In a presenter of her age, these are indeed unusual qualities. But try describing her as a "female" presenter and she'll bite.

"When I was growing up I loved people like Iggy Pop and Vic Reeves, Kim Gordon and PJ Harvey - this sort of really weird selection of icons," she says. "My role models were never defined by gender and I don't think broadcasting should be either. People sometimes say there are too many men on Radio 2 but as long as they're all good, and the best around, that's the way it should be. I think there are more interesting conversations to be had than the ones about gender."

One such conversation involves her eight-month-old son, Fergus, who she says is "pretty awesome. Motherhood is joyful and very difficult and all the things that everybody always says it is. He's not one of those babies that you can plonk down and get stuff done. He's got a baby walker so he can actually glide around like the nun in The Blues Brothers.

He moves round the kitchen vaguely menacingly, going up to the fridge and going, Ba ba ba'." She had wanted to name her son Hunter, after the writer Hunter S Thompson, but her married name is Fisher and "Hunter Fisher was just never going to happen". As the first grandchild, the boy has drawn her already close-knit family even closer.

"I think my parents are more proud of me for having Fergus than for anything I've done professionally," she says.

The inevitable question as to how she balances motherhood and a demanding media career has come in every shape and guise since she gave birth, and it's not one I particularly feel like repeating. But still ...

"It depends on how strong your sense of priorities is and mine's absolute," she says. "My family's always been the most important thing. Logistically, of course, there are difficulties, but there's not been a massive sea change where I've gone from being a career girl to being a mum'. There's a certain amount of hours in the day and you divide them up as best you can. I'm very aware that I'm incredibly lucky to have the job I've got and I know a lot better than to complain about it."

Minutes before filming begins, she disappears into her dressing room and reappears transformed. She stands in a black frock and blue four-inch heels. Her hair and make-up are done and she looks like Lauren Laverne from the television.

She admits to feeling "nonplussed" when people compliment her performance on The Culture Show because she is "only introducing stuff", as if she still hasn't quite worked out what sets her apart. "I always think that TV presenting is such a doss, but then I suppose some people do find it hard to do," she says.

"It's not that I think I'm any good at it. I just think everyone else hasn't worked out how easy it is."

First published in The Sunday Herald, 2008.