Ruben Madsen of the Surstromming Academy in Sweden traveled to Norway to take care of the can, which had been on Inge Haugen and Bjorg Hennum's roof in Tyrsil since a party they held in 1990, TheLocal.no reported Tuesday.
Madsen, who was contacted because the couple started to fear the swollen can of fish would explode, said the first thing he noticed when he opened the container was the odor.
"The smell was terrible," Madsen said. "At first when I opened the can, it smelt really good, but within 15, 20 , 30 seconds, when the oxygen started to affect the brine, it started to smell really, really bad. Normally surstromming smells really aggressive, but this was worse. It was terrible."
Madsen said he found the herring had completely dissolved into the brine.
"The release was a big success but the opening was a big mess," he said. "It was impossible to eat. It was some kind of rotten porridge. It was impossible to taste it."