The social enterprise, which ran apprenticeships for young people from disadvantaged backgrounds, was one of 22 sites which closed when the Jamie Oliver Restaurant Group entered administration in May.
In an interview with The Times, Oliver said: “It was very, very upsetting to have to close Fifteen. We died. It was tough. I’m not going to lie; it was really bad."
Since Fifteen opened in 2002 it has trained 15 young people a year to work in the food industry, at a cost of £40,000 each. Oliver said more than 80% were still employed in the sector five or six years after they left.
The chef told The Times he hopes to bring the project back in some form. Fifteen Cornwall, which is now run by a separate charitable trust, remains open.
“Really, there’s nothing like it, even now. I think it’s heart was in the right place. It’s completely changed me that business. The young people who graduated were the profit, really.
“Fundamentally, Fifteen was about social mobility. That’s a phrase I’ve only learnt in the past few months. But it’s so important.”
Oliver also spoke about the collapse of the wider Jamie’s Italian chain, and claimed he was badly advised on the state of the company but took “full responsibility” for its demise.
“I am not going to have the wool pulled over my eyes or suffer from a lack of clarity again,” said Oliver.
“At the beginning…no one sat me down and asked me if I had a plan B in case it goes down the toilet. When it was all going wrong it felt like a colander: the business was full of holes and there was nothing we could do to plug them.”