Alexander McCall Smith is not an easy man to pin down.

The prolific author, best known for his No 1 Ladies’ Detective Agency series, is also Emeritus Professor of Medical Law at the University of Edinburgh and a sought-after speaker at book festivals around the world.

“One of the problems with becoming a full-time writer is you don’t have time to do any writing,” he jokes, during a snatched eight-minute interview at Wimbledon BookFest.

This is clearly not true for McCall Smith, who is on track to release seven new novels this year.

He says his secret is getting up at 4am, to write for the first four hours of the day, before distractions get in the way.

“There’s a very pleasant atmosphere at this book festival,” he says.

“Some book festivals are very, very big but this is a nice size. It’s not too small, not too big, rather like Mother Bear’s porridge in The Three Bears.”

Wimbledon Village seems an apt setting to meet the affable McCall Smith.

Its green Common, luxury delicatessens and disproportionate number of ambitious mothers and writers wouldn’t be out of place in his 44 Scotland Street portraits of middle-class Edinburgh.

Would he consider setting a novel here?

“No, I don’t know anything about Wimbledon”, he confesses.

He’s really in town to talk to Jennifer Cox about his adaptation of Jane Austen’s Emma, part of a project inviting authors to reinvent Austen’s classics for a modern audience.

The book will be released in November, of which he says, “I’ve never had so much fun in my life, not since I was in the boy scouts. I wrote it in about two months and at the end I felt bereft because I so enjoyed being in the company of Mr Woodhouse and Emma.”

McCall Smith’s highly-acclaimed Emma transports the much-loved protagonist to the 21st century where, just out of university, she launches a design business and makes an impact in the Norfolk village of Highbury.

He says he considered setting the story in the seaside town of Tobermory on the Isle of Mull in western Scotland, but changed his mind as Austen is so “quintessentially English”, it would be an act of “cultural appropriation.”

One cannot help but suspect this was a tactical move, with the Scottish Referendum looming while he worked.

However, he remains tight-lipped about his opinion on the result.

He explains, “It’s been a very, very bruising and unhappy few months in Scotland. I don’t discuss that publicly because it was a very traumatic time for everyone.”

Sadly, for the 350 fans who flocked to the main tent on Wimbledon Common to hear McCall Smith on the BookFest’s opening night, he’s not in town for long.

Quite romantically, he returns to his beloved hometown of Edinburgh via the sleeper train, leaving Euston just before midnight.

Before he gets away, I can’t resist asking for a few of his writing tricks.

“Persist”, he says. “Write from the heart, and persist. And don’t spend too much time on your first manuscripts. A lot of people spend an awful lot of time polishing it, re-writing it. Move on to the next one, that’s my advice.”

Wimbledon BookFest runs until October 12. For tickets, visit the website.