What Paul gets up to is his business

She's got more zest than a lemon and a centre softer than a pavlova. The nation, it seems, has gone bonkers over 'Berrymania'.

As a judge on The Great British Bake Off the rise and rise of the diminutive Mary Berry has whipped up quite a storm.

A household name for decades, it took the phenomenonal success of the programme to turn her into an A-Lister in her 70s.

And it's not just the twinset and pearls brigade who are fans. Baking has never been so trendy with Mary inspiring a whole new generation of young cooks to put down their iPads and get creative in the kitchen.

In fact, it's become such compulsive viewing that, according to Mary, footy mad men are even sidelining the beautiful game in favour of tips on how to make fondant fancies.

"The series is now watched by 6.3 million people and a lot of men are tuning in. It is a cult."

So just what is the ingredient that makes the Bake Off - where amateur bakers offer up their confections for scrutiny by Berry and fellow judge Paul Hollywood – a TV ratings hit?

While other reality judges rant and rave and are as rude as possible, the Bake Off critique is much more measured, tame even.

Yet the unlikely combination of mild-mannered Mary – who appears more WI than reality TV judge – with baking pro Paul keeps people glued to their screen.

While Paul's direct approach could deflate the fluffiest of soufflés, softly spoken Mary sugarcoats her comments. "It's a winner for flavour" she says of crestfallen contestant Ruby's under-proved mango and Nigella seed spelt cob.

Can you ever imagine foul-mouthed Gordon offering crumbs of comfort if a contestant's cake collapsed?

For Mary it's all about encouraging the bakers and instilling the confidence to experiment with ingredients.

While she doesn't want the competitors beating themselves up over a disastrous dessert, as the final looms even Mary admits to being a bit of a tough cookie.

"We want people to do well. We want people to watch the Bake Off and actually bake at home, not put people off and frighten them and get cross with them.

"I think the reason the show is popular is because it is a very natural show. The contestants are all amateurs and that's very important and people see what good bakers can achieve.

"I'm encouraging people to bake. I think that's very good, it gets the family together. It's something you can do at home, it's creative and it doesn't cost too much."

The programme's wholesome image has recently been compromised by rumours Paul Hollywood cheated on his wife. The allegations have caused quite a stir but Mary is adamant it's none of her business. "It's up to Paul what he does, it's nothing to do with me, it's Paul's life.

"We are good friends, we are both professionals and we have a great time on the Bake Off, he is brilliant at what he does and that's why he's there."

But what of reports she excused his antics saying "boys will be boys". "I didn't say that," she says emphatically.

Something else that's caused a bit of a stir is Mary's neon wardrobe.

She was flabbergasted by the fuss over her Zara floral bomber jacket when hundreds commented on social networks. How does she feel about being a fashion icon at 78?

"I don't know about that, I do my best," she laughs. "I like bright colours – well we need to cheer each other up there are plenty of grannies in grey.

"I try and wear a different jacket and jumper each time and quite enjoy choosing it and I think people look forward to seeing what I've got on.

"When you're older it's essential to be really comfy and not to wear anything too tight or too short and cover up those arms. I try to dress for my age in things that suit me and that my daughter approves of."

So what about your fellow judge, what does he think? "He couldn't care less what I wear but I keep telling him he looks nice in his shirt."

Styled the Queen of Cakes, one of Mary's biggest fans is the Duchess of Cambridge.

"I know she uses my recipes which is lovely because they are very simple family recipes and she is very much a family person," enthuses Mary, who met Kate and Prince William at an event for Child Bereavement UK.

"I thought she was absolutely delightful, very sincere, very interested and of course she is a really keen family person especially now she has little George."

Both Prince William and Mary are patrons of the charity. It's a cause close to Mary's heart. Her son William died in a car accident, aged just 19, and at the time she felt there was little support for bereaved families.

"I was lucky to have a wonderful husband, a lovely family and very good friends. You just have to go on."

Family is clearly very important to Mary. She has been married to Paul, a retired antiquarian bookseller, for almost 50 years and amazingly they never have a cross word.

"For better or worse," she jokes."He's my best friend. I think a marriage is made, don't you? There are times when you might have an argument, well I don't have them, I don't like them." Mary also has two other children Thomas and Annabel. "My children all love cooking but then so they should. They are good cooks, Annabel is very adventurous and Thomas cooks with great speed because he's always ready to eat it."

Teaching schoolchildren how to rustle up delicious, healthy meals is something Mary champions.

She wants the Government to make cooking lessons a compulsory part of the curriculum. That's why she's pleased to hear that from next year primary schoolchildren will be taught basic cooking skills and how to make a balanced meal.

"Children are going to leave home at some point and they've got to fend for themselves so they need to be taught 10 healthy meals they can achieve themselves.

"Parents are often too busy to teach them cooking so I think it's up to schools to teach them and not just the science of food. They need to know about actual ingredients and the use of fresh fruit and vegetables."

It was her domestic science teacher Miss Date who first inspired Mary. She recalls a treacle pudding she took home which her father declared to be "as good as mum's". High praise indeed, "I felt pretty proud," says Mary.

A plethora of cookery books later and a CBE to boot, Mary has well and truly proved she knows her treacle puddings and her sponges, scones and souffles too. She'll be demonstrating her expertise at Cake International – The Sugarcraft, Cake Decorating & Baking Show at Birmingham's NEC from November 8 to 10.

Mary is looking forward to the show and meeting what she calls the "real bakers" and says the event always attracts a great crowd.

Life for Mary couldn't be sweeter right now. "I was so pleased to be asked to be a judge on the Bake Off and it makes for a very interesting life.

"I'm doing something I know about and I'm enjoying it enormously."

Of the show, Mary says it's the mischievous antics of presenters Mel and Sue who help keep the competitors' spirits up.

"They are the funniest thing about the programme. They make all the bakers relax and keep the humour level up, going round pinching sweets out of the jars."

What's less easy to laugh about is when – the culinary calamity to beat all others – you drop your beautifully baked cake on the floor, as a contestant did in an earlier series.

Mary says: "He managed to pick it up and reassemble it and it could still be judged.

"It's very interesting how people cope in emergencies. Too often something doesn't turn out and they patch it up, put a bit of icing over it, that's how life is."

By Heather Loat