Owen Foster, 18, started Owen's Angus Jams from his mum's kitchen when he was just 14, and is now producing thousands of jars a year for shops, cafes, restaurants and even a luxury castle.
He was inspired by his gran, Joyce Morrison, 69, and asked her if she would teach him to make homemade jam, using natural ingredients and traditional methods.
The first batch all sold out within a week, at £3 per jar.
Owen, from Forfar, Angus, had initially sold free range eggs around his hometown but realised jam-making could be more profitable.
He initially sold it door-to-door and at a market stall, but it has now become his full-time job after leaving school at the age of 17.
Owen said: "It's my full time job. When I was 12 I was selling eggs, but the supply dried up.
"Then I went to my gran and asked her to teach me how to make jam. Every summer grandma would make jam - she learned it from her mum. She loved just giving it away.
"We made a pot of 50 jars and sold all within a week at £3 a jar. I thought 'I could buy a lot of sweets with that', and it just grew from there."
Word soon spread about his tasty preserves and he has now expanded his selection to nine different flavours - including raspberry and blackberry, strawberry and pink Champagne and traditional favourites, raspberry and strawberry.
His strawberry, rhubarb, apple and cinnamon jams and Seville orange marmalade have won 'Great Taste' awards.
Owen was thrilled when local stately home Glamis Castle awarded him a contract for making jam - with American tourists putting in orders as a result.
Last year he made 1,000 pots of jam for the castle. Owen said: "Our first main contract was Glamis Castle.
"They took our jam and did a taste test and we won. Last year we made 1,000 jars for Glamis. We can't do supermarkets because of the way it's made.
"The jam in the shop is factory-made and contains additives and preservatives, like gelatin. A lot of people wonder how we get our strawberry jam to set - there are a few tricks to it.
"We do catering jam that a lot of cafes and shops take. We sell stuff through Facebook and have posted it over to America."
Having upscaled from his house to an industrial unit, Owen is in the process of relocating again to a building which he is looking to turn into a production space and a farm shop.
He said: "It started in my mum's kitchen on a small stove till about last year, then we got a premises in an industrial unit.
"I'm moving again to a place with a kitchen in the back with a farmshop and space for a cafe.
"We weren't looking for a new place but it came up and thought it was too good to pass on and the scope for growth is much higher.
"The public can come and see what we're selling, so demand will grow.
"It must be about 3,000 to 4,000 jars this year.
"We're looking to upscale but by doing the farm shop we're looking to branch out and get other local products in."
He also makes fruit infused gins and sells his products online as well at markets.
His accountant mum, Judith, taught him the ins and outs of managing his own accounts.
Owen said: "At the moment I'm making it all, jarring it and labelling it.
"Me and my mum run Facebook and social between us. The staples are raspberry and strawberry."
Gran Joyce said she was "proud" of Owen's success so far in business.
The grandmother of 16, from Blairgowrie, Perth and Kinross, said: "It's exciting and we're extremely proud of him. He can see his way forward and we'll support him.
"He certainly has that entrepreneurial spirit."
Owen added: "I've enjoyed it. It's been really good to get the learning experience.
"Normally people my age don't do this kind of thing."