15x15, Radio 4, Sunday<br/>The Real Apprentice, Radio 4, Monday

In bed with Hardeep, master of the mattress

Hardeep Singh Kohli has a lovely touch – few Radio 4 presenters could greet a mattress-seller in an Islington market with "Hey, bro" and not sound like a nitwit. His charm was deployed to great effect in the first of a new series, 15x15, in which he takes a word and sets out to learn 15 facts related to it (starting with "mattress", hence the shopping trip).

The title's a bit of a misnomer, alluding more to the programme's length than the number of facts, but Kohli makes it all work.

He talked to a soprano, Julie Unwin, about playing Tosca, who famously chucks herself off the battlements – requiring a mattress to break her fall. Unwin told of an unnamed diva who'd upset the crew once too many times; on the last night they removed the mattress and replaced it with a trampoline. "She reappeared a few times," Unwin reported.

The star, though – total star of the week, in fact – was bedbug man David Cain. "I have inspected, rotated and generally poked and prodded around twenty-five to thirty thousand mattresses in the last eight years," he said in his slow, painstaking manner, explaining that he looks for live samples, faecal traces and cast-off skins. Kohli asked him what he does when he checks into a hotel.

"I put my bags into the bath," he said, "I put my head torch on, put my examination gloves on, and I spend three to five minutes dissecting and examining the bed. Every single time I stay away from my own home – doesn't matter if it's a hotel, my parents' home, a friend's house, even a new romantic interest in my life – I will inspect the bed every single time."

"That's going to be a passion-killer, David," Kohli advised, perhaps unnecessarily.

"I keep colonies of them in special jars on my desk," Cain continued.

"Oh no," Singh Kohli groaned. "What do you feed them on?"

"Me," Cain cheerily informed him, pressing his forearm against the jar-top gauze. "I love them," he said.

"They would appear to be loving you," Singh Kohli said grimly. "I think you should stop now, David."

I don't know if Cain has apprentices, but I can't see today's feckless youth fancying the job. Construction's another matter, and The Real Apprentice followed seven young men competing for one building apprenticeship in Newport. "It's a job for life, isn't it?" the winner said with admirable optimism.

Presenter Jon Manel inspected a 15th-century document detailing the agreement between a butcher and his apprentice. It was a 12-year deal, without wages – in fact the lad's mother was paying 100 shillings. He couldn't get married or engaged, and he had to agree to keep his nose clean. You try telling that to the kids of today.