Magistrates in York were told that Alex Tuvey-Smith, 36, was left in intensive care after plunging into a hot peppermint Aero machine he was cleaning at Nestle UK's factory in York last August.
Bill Cook, for the Health and Safety Executive, said staff had failed to isolate the power to the Aero mixer. While cleaning excess chocolate off the sides of the mainly empty, metre-tall machine, Mr Tuvey-Smith had the lid (which acted as a guard) removed for greater access.
He had then been able to lean in up to his waist but had slipped and fallen in. As he did so the paddles started up automatically, spinning him round for more than a minute and causing him severe injuries. He broke his leg, pelvis, hip, two ribs and two vertebrae, and was in hospital for more than two months. He is still unable to walk without crutches and may remain permanently injured.
Mr Cook accused the company of 'confusion and complacency' after it admitted failing to ensure the safety of Mr Tuvey-Smith.
As well as fining Nestle UK, which is based at Croydon, south London, pounds 12,000, the magistrates also ordered the company to pay pounds 1,095 costs.