Chris McCabe, 70, said he got trapped after the freezer door in his shop in Totnes, Devon, blew shut behind him.
Stranded in temperatures of -20C (-4F), with the door-release button frozen shut, he said he used the 1.5kg (3.3lbs) sausage as a battering ram on the release mechanism.
Mr McCabe said: “No-one could hear me banging. Black pudding saved my life.”
Upon realising his predicament, Mr McCabe initially thought he “was OK because I could kick the safety button from inside”, but “this time it was frozen solid”.
Stuck in temperatures capable of killing a human in about an hour, the father-of-four searched frantically for an improvised tool to batter the button.
With the beef too slippery and the lamb too big, he happened on the “best thing” – the black pudding, made by the Queen’s butcher HM Sheridan of Ballater, Aberdeenshire, who Mr McCabe has been buying the pudding from for more than 20 years.
He said: “It was the right shape. I used it like the police use battering rams to break door locks in. It was solid, pointed and I could get plenty of weight behind it.
“I’m lucky really. We sell about two or three each week and that was the last one in there.”
Full story from the BBC