olly Pan Drops, Soor Plooms, Chocolate Italian Creams, Rich Butter Treacle, Cinnamon Balls, Liquorice Comfits. The names of the sweeties reel off my tongue, taking me back to summers spent in my mum's car, when I "helped" as she sold boilings, toffees, chocolates and fudges to the corner shops and cafés of the west of Scotland.

I was five years old when my mother, Christine, became a "sweetie lady", selling twinkling jars of sugared delights for Buchanan's, a traditional confectionery company then most famous for its waxpaper-wrapped toffees the size of an old penny. Each day she'd get up at dawn, meticulously apply her make-up and put on an immaculate suit and high heels. She ate a good breakfast, then, picking up her order book and applying a last coat of lipstick, she'd head out of our Glasgow cul de sac in her company car.

This summer, after 38 years on the road, Mum handed over her car keys and put down her paperwork for the last time. At 65, she was persuaded by my father that she should say goodbye to this life in sweeties – those wet, west-coast Scottish winters were taking their toll and the time had come to relax. It was not something she did with relish. Christine was saying farewell to customers who'd become great friends. It was as if not just a way of working but a way of life was coming to an end.

In an age of iPads and iPhones and PDAs, my mum's business relied on the personal touch, travelling to find out people's needs, writing their orders down with a pen and paper, placing them in a stamped, addressed envelope and sending them off to a factory in Fort Matilda, Greenock, where they would be processed, packed by hand and sent out in a lorry that made daily deliveries.

It was a life marked in six-week cycles that took in seaside towns as well as bleak housing estates. Through it my mum built her own community – every six weeks she garnered news of marriages and babies, holidays, first days of school, graduations and, of course, deaths. With only a car as an office, the shopkeepers and café owners became my mum's "colleagues", the anchors that helped bring a sense of stability through peripatetic years.

In those early days, a lack of childcare during school holidays meant I sometimes accompanied her, sitting in the back with the jars and piles of paperwork and the folders full of glossy pictures of her wares.

As the days counted down to her dreaded retirement, I wanted to get a sense of what it was about her that made her the company's salesperson of the year, almost every year as far back as I can remember, and I wanted to meet some of those customers she never stopped speaking about. As I grew older, I sometimes listened to their voices on the telephone, listing the beautiful, mellifluous words as I wrote down their orders for Buttered Brazils and Rich Treacle Perfection. But I'd never seen their faces. I knew that over these six weeks my mum made 500 calls to shops such as Olga Quintiliani's Sweet Stop and the Tommy Tango Candy Store. Her favourite journey was the one that took an extra 15 miles of driving but brought her to Arrochar and Luss, lying within the shadow of Ben Lomond. On Glasgow's Byres Road, at the very heart of the lovely West End, lay the Art Deco University Café, where a roll and fried egg and a cup of coffee would be laid out on a narrow Formica table by one of the many members of the Verrecchia family who worked there.

We pull up outside Swan's Sweet Shop, a small building that's been in the West Dunbartonshire village of Renton for 56 years. The only shop for miles, it is at the heart of the community. My mum looks in her rear-view mirror at the passing traffic and tells me of the time when she was parked on the same spot and a heavy-goods driver shunted her car along the street just as she was getting some samples out – she ended up in the back with the sweeties while a man shouted "Haw, stop, there's a wummin hinging oot that boot!"

"I've been coming to Tom Swan's since I started the job, which was April 1973," she explains. "It's a quirky wee shop; none of my other calls are quite like this. It's an excellent place for people to reminisce. They travel from quite far and wide just to get their sweets here." From the outside, it's difficult to imagine what makes this place a kind of sweetie mecca. But the smell that sweeps over you as you step inside takes you to a nostalgic place that is soothing. Tom's is full of memory jolts for the eye and the tongue. Its draw is so strong that there's even an Official Tom Swan Appreciation Society on Facebook.

I notice my mum scanning the warping shelves, looking for her jars, measuring how full they are and assessing what Tom's going to need. She liked the jars better when they were glass, she says; the plastic ones don't look as nice when the light hits them. I can't see what she means because there is no natural light in Tom's shop – jam-packed with sparkly wrappers, luminous colours and shouty lettering, the place seems to heave under the weight of all that sugar.

At first Tom, 75, acts the curmudgeon, looking at me with disdain: "So, you're the wonderful daughter? I'm fed up listening to her going on about you." But soon he and my mum slip into an ease that comes with meeting every six weeks for nigh on 40 years. She just laughs when he says: "I used to look forward to seeing her when she was younger. She was dressed to kill then."

I ask Tom what makes my mum so good at her job. "She's no a good saleswoman, it's just the stuff that's good," he chimes. "If it's good stuff a monkey could sell it." Tom tells me that there used to be many more travelling sales people on the road, but my mum was only one of about three "wummin" reps. She nods: "You used to have to stand outside if there was somebody in because there was that many travellers. And that was every shop that you'd go into. There was no cash-and-carries then."

A woman comes in with her grandchildren, here to buy sweets to take to her brother in Florida. Tom shoogles a jar to loosen the boilings, then comes a waterfall hitting the metal pan of the scales, first in one big crash, then softer as he gently tries to get the right weight. Bagging up some Rhubarb and Custards, Tom explains that men buy the gums, Sports Mixtures, Midget Gems. Women, he says, like fancy chocolates, chocolate creams, mint creams, Italian creams. "The generation under 18 – they're not used to the hard stuff, the boilings. Young yins look at boiled sweets as if it's poison if I let them try one. But old people love boilings – it's helpful for their memories. They don't mind of their husband, but they mind of the sweets."

A customer comes in and knows what he wants: "Gie us a Mars Bar and an Aero furra dug." Tom says he only has the pound Aeros. "That'll dae," says the man, unwrapping the bubbly chocolate for the animal tied to the lamppost outside.

I tell Tom our family had a strange relationship with the sweeties. They filled our house and our garage, the back seat and boot of the car and they acted as a kind of sticky Pied Piper, bringing children to loiter round our gateposts, hoping to score some of the samples of new lines or gone-soft toffees that were being sent back to the factory to be disposed off. But we – my dad and I – weren't allowed to eat them. I remember the warnings: "You'll get fat, you'll rot your teeth," which seemed ironic coming from the woman who made a living selling the bringer of such ruin. Resisting the temptation of the sweeties was my mum's cardinal rule. "I don't have a sweet tooth," she says. "I never have done."

Buchanan's was a family business that began when a boy took 7lb jars of his mother's home-made jam and sold them from a handcart around the Loch Lomondside village of Drymen. Soon the family bought a shop in Glasgow's Argyle Street but, as Scotland's addiction to sugar grew, they moved into sweet-making in 1856, producing their concoctions in a five-storey factory in the city centre. They were on to a winner: Scotland now consumes about 8oz of sweeties per week per head of population – the second-highest consumption in the world, beaten only by Northern Ireland. Here, there's a preference for boilings over chocolate as you get more for your money.

These days Buchanan's is part of the Golden Casket group, another family business, which operates out of Greenock, a port town on the Clyde coast once known as Sugaropolis because of the number of refineries that took the cane from ships coming from the Caribbean. Tate & Lyle, Walker's and the other refineries have all gone now. The red sandstone Golden Casket factory is at Fort Matilda, the site of a former torpedo plant, and the very first time I heard its name it took on a mythical status for me. Like Charlie Bucket, I wished to visit the place where they made the world taste good. It took me more than three decades, but my mum's imminent retirement brought me my golden ticket.

Driving down the M8 towards Greenock, my mum makes an odd confession: she's never actually been on the factory floor. As we pull into the car park, the air around Fort Matilda smells of sugar, mint and lemons – it changes by the hour, depending on what's being made inside. Mum is too nervous to notice: her legs are shaking. She's carrying a box with six bottles of wine for the girls in the office but falls over as she makes for the entrance. She picks herself and the wine up as if nothing has happened. In the boardroom, The Boss, the fearsome Douglas Rae, is waiting for us and my mum is worried: "He's a stickler for timekeeping." The Boss is 80 years old, a whippet of a man who still goes out on the road selling, runs the company and holds down the chairmanship of Greenock Morton football club. He can't believe my mum is walking away from his sweetie empire, so much so he has asked her to stay on for another five years.

"She's good at the job and she's too young to leave – that's what I believe. Nowadays people can last for years. If people have lost their enthusiasm then I am glad to see them go," he points to my mum's face as he says this. "Look how it has kept her beautiful, it's the rain that keeps you beautiful." At the annual dinner dance, Mr Rae would present my mum with the salesperson of the year award almost every year. But what made her so good at this business? He thinks for a few seconds and says: "She's a very strong character and she likes to have her own way. She's a bit of a bully, she bullied all her customers – they were all afraid of her. They couldn't say no. That's a quality I admire."

In the factory, the sweetness and noise is overwhelming; cream-coloured machines thump and judder and conveyor belts carry candy-striped jewels. Men in overalls, aprons, gloves, hats and wellies work between tables of fudge, toffee and tablet. In the boiling section, a batch of striped mint humbugs is being prepared. A man with giant scissors is cutting into a tray of molten sugar. There are 25kg bags of sugar lying all around and behind us two enormous copper boiling vessels are being filled with butter, sweetened condensed milk, sugar, glucose and "secret ingredients".

"All the pans we have are open vessels because we believe traditional methods are by far the best," says Crawford Rae, the production director, and son of Douglas. "The real secret is the methodology. That's why big Gus is turning his back there so you won't see what he's trying to do. It's all intellectual property, the staff are life members of a secret society and there are serious repercussions if they break that code." As he stirs the toffee, Gus is laughing.

Some of the equipment dates back to the 1920s, but the hand-dropping method is no longer used for the toffees: times change and new contraptions take over. Last year a machine arrived from Italy and since then it has wrapped 61,489,606 sweets. I wonder how long it will be before hand-held computers make the travelling salesperson obsolete. The Boss looks aghast: "It's not all the people that can download things on the computer. Unless you're going to teach people things on the computer, the written word, I still believe, is the best."

From Fort Matilda, we drive to the posh dormitory suburb of Giffnock to meet Willie Wark who, like his father and grandfather, worked for Buchanan's all his life. Willie, who retired 16 years ago, says: "Long before the days of cars my grandfather would go to, say, Ayr railway station and there would be a traveller for sweets, somebody who sold cigarettes and somebody for biscuits and they hired a gig together and went trotting off round the wee villages in Ayrshire. And they used to stop outside a shop and they would toss up to see who went in first. They would stay away for a week, and they weren't any further away from here than 20 miles. I bet it was faster with a horse and cart than it is these days."

We head down towards the Brooklyn Café, which sits at a busy crossroads on Glasgow's south side. Now, it is one of only 20 Italian cafés called on by my mother, when once she visited more than 80. This year, David Pelosi is celebrating the 80th anniversary of his family's business and he shows me a picture of his Italian grandfather – a former organ grinder – standing proudly outside a window full of chocolate boxes and jars of sweets. "We had more sweets then," he says. "Our stocks have diminished now as people buy from petrol stations and supermarkets. But jars are part of our history."

Saying goodbye to my mum, David tells me he'll miss her. "I take it a new rep will come in and we'll build up a relationship with them. But it might go the way other companies have gone where the rep has less and less importance and we do more of it over the phone."

Across the west side of the city, in Knightswood, Sunil Sood and his wife Fiona are waiting in their post office with a bottle of wine. Christine first called on Sunil's father 25 years ago, moving on to each of his four sons as they opened up their own businesses. "From Hyndland to Crow Road, from Crow Road to Thornwood and from Thornwood to here, she's been stalking me since 1986," jokes Sunil, as he takes a pen and fills out the order form for 720 packets of boilings himself. I ask why he doesn't just email it in. He looks astonished. "Because I need somebody to talk to, to have my cup of tea with and my biscuit." As we walk out, Sunil shouts after my mum: "That's you a senior citizen. Do you want a wee bus pass? I can process it right now for you."

I think back to the factory and my mum staring in wonderment as the sweets popped off the conveyor belt at high speed and into the cooler. She didn't look like a pensioner then. Her eyes were bright and wide, just like the kids in Tom Swan's. I caught her reaching out and taking a sweetie from a conveyor belt, popping it in her mouth and chewing. She had broken her cardinal rule. "The toffees just looked too tempting not to take," she said. She had such a naughty look on her face.

A Life in Sweeties will be broadcast on BBC Radio Scotland on 28 December at 2pm