A love of telling tales and tightrope walking

There the Shed changes shape and location every day so a little while ago it was a hot air balloon of paper and blue taffeta, inscribed with signs of the zodiac and painted with mythical creatures. Another day it was transformed into a sunken ship, just glimpsed through curtains of seaweed, with a fat black cat sitting under the deck as the monsoon rain fell.

A prolific tweeter, the author of Chocolat, Blackberry Wine, Five Quarters of the Orange and The Gospel of Loki says she has a lot of fun with social media, not just passing comment on the subjects of the day but going back to the very roots of the storytelling tradition.

"I make up stories and tell them as I go in tweets so there are people who will know I'm doing this and they'll get a cup of tea and wait for the next tweet," she explains.

"It's a funny one because I know certain people who put stories on Twitter but they've already written them. I haven't already written them, I just start and I think: 'OK, I'm just going to walk this tightrope and see where it leads.'

"I do it every two or three weeks but it's an interesting exercise and not one I'm able to do in any other context because I have an audience.

"It's very interesting. To me it's the line between the oral tradition of making up a story and telling it to an audience and the written tradition of writing it down.

"To me, writing a story on Twitter is exactly in the middle because you are effectively telling a story live to an audience. It's a big audience and they're all over the world and you don't know who they are a lot of them, but that's what it is."

She may be embracing social media but the printed word is very much on Harris's mind when we sit in front of a roaring fire in the library of the Victorian house she shares with her husband and daughter, every shelf jam-packed with books. She was invited to be an author-ambassador for Book Week Scotland, and Harris is supporting the love letters to libraries and the reading pledge campaigns.

She vehemently opposes the closure of libraries across the UK, railing against "the idiots who are behind this who are not going to be there to see the consequences".

Then she stops, laughs and looks around: "You can see I probably don't need a library in terms of the amount of books I've got here but I do need it as a public resource.

"I need it as a hub of the community. I go out to libraries, do events in libraries, it's not just about a place where you have books, that's a very naive interpretation.

"It is the great leveller because they're free, they're open to anyone - when people are complaining about the price of books and pirating books online and saying: 'How else can we get them free?' the library is the answer to that.

"People would like books for free and they've got them in the library. Poor people, older people, the children of people who can't afford to buy a book every time they want to read it or study it, they've got the library and what's more they've got, so far at least, trained librarians who are also in themselves a resource and a very valuable one."

Harris was working as a teacher and writing in her spare time when sales of Chocolat, her third published novel, went stratospheric.

From sun loungers to book clubs it was read and devoured like the most mouthwatering of sweet treats, topping bestseller lists, winning awards and eventually being turned into a film starring Johnny Depp and Juliette Binoche. The sweet taste of success saw Harris take a sabbatical from teaching, then concentrate on writing full-time, swapping the classroom for book tours and signings.

But she hasn't fled to the bright lights of London, preferring to stay in Yorkshire with her family and the friends she has known all her life.

Contrary to popular belief, she doesn't spend part of the year in France: Harris was born in Yorkshire (above a corner sweetshop in Barnsley) to an English father and French mother. And though there are references to magic and folklore she has no occultist or pagan links.

"My world is the same as everybody else's world, it doesn't really change that much. My preoccupations are still very much the same, my family is still there, they still do the same things and I still do the same things," Harris says firmly.

"I have done a number of interesting and quite unusual things around this job which generates interesting things. The core of things is pretty much the same."

What has changed is the number of attractive offers that now come her way: she tells me she is meeting music producer Mike Batt for dinner later in the week, though she can't talk about the project yet, and earlier this year she penned a Doctor Who novella to great acclaim, which is no mean feat when you consider the depth of feeling fans have for the Time Lord.

Doctor Who: The Loneliness of the Long-Distance Time Traveller was time-consuming, says Harris, but a lot of fun, taking her back to being a child in the 1970s as she chronicled the life of the charismatic Third Doctor.

"Writing anything in the Doctor Who universe, you are part of a very, very intricate infrastructure of other narratives and anything that gets put in has to fit perfectly with everything that has ever been done in Doctor Who at any time within that canon, which makes it quite a tricky thing to do. Particularly if you're trying to go back, which is what I was doing," she says.

"It was a bit like travelling in time for me: I was going back to the 70s and being a child. I was writing about the Doctor I had known since I was six. It was an interesting process and I would do it again. Of course there's this tremendous weight of expectation from Doctor Who fans, who have been very good."

Success has also given Harris a voice and she regularly speaks out against sexism in the creative arts and the very notion of categorising women's fiction.

A graduate of Cambridge, where she read modern and medieval languages, Harris furiously hits out at why we still need women's prizes for literature, misogynistic attitudes to women in the publishing world and the term chick lit. "It demeans readers and writers alike, in my view.

"There is this unspoken feeling in the industry, which is quite widespread, that women write for women and that men write for posterity, which is beyond rubbish and is still perpetuated.

"I still meet people who should know better, men usually, who say things like: "I never read books by women". As if that was meant to be something to be proud of. As if that kind of ridiculous, sexist affirmation were something that made them sound clever.

"We need to correct this, which is why we've still got women's prizes - not something I particularly approve of, I've always felt prizes should be open to everybody - but they're not open to everybody because there is still a preponderance of men in the major literary prizes and women need to be caught up in some way, they need to be valued and there needs to be a platform. The day there doesn't, I will be very happy."

When I leave and Harris returns to work in the Shed, Vlad, her adopted black cat appears, at the back door, stretches and comes to greet us.

He's not lost at sea today, though who knows what world Harris will transport him to in her stories.

Joanne Harris is an ambassador for Book Week Scotland 2014, a national celebration of books and reading running from November 24 to November 30. www.bookweekscotland.com.