The waiter, identified by the German press as Martin D., said he could not stop himself shouting out a profanity as the glasses slipped off his tray, pouring beer down the back of the country's leader.
“A colleague should have brought her the beer. But she was so nervous, she asked me to do it for her,” the 21-year-old told Bild newspaper.
He described the moment he lost control of the five glasses of beer as if it had happened in slow motion. “I was shoved from behind, and tried to catch the beers, but it was too late. I shouted “Shit!” really loudly,” he said.
Merkel kept her cool though – appearing less upset than in 2006 when the then US President George W Bush took her by surprise with a shoulder rub.
Her reaction to the Texan's spontaneous physical contact has long been a Youtube classic – but beer down the back seemed to bother her less.
“She turned around, grinned at me – and even though she was wet, went to the speaker's stage shortly afterwards,” the waiter said.
Merkel's Ash Wednesday speech at the Demmin Christian Democratic Union meeting should have been an easy one for her – the little town is in her home state of Mecklenburg-Western Pomerania.
She studiously avoided mentioning the troubles swirling around her – not only a beer-soaked jacket, but also the resignation of her choice of President and the continuing problems with coalition partner the Free Democratic Party.