Father Kevin entombed the Catholic relics under the side chapel of the Cathedral of the Blessed Sacrament nearly 50 years ago in 1975.
They were unearthed again after the earthquakes when the cathedral was demolished.
Christchurch diocese archivist Triona Doocey said why he chose coffee jars and other pantry containers as the vessels remains a mystery.
"It was just a really practical solution because you need something that's air tight, water tight, that's going to protect them and the jars did the job.
"There was one other jar that did leak, and that was a jam jar rather than a coffee jar. So if you're doing a time capsule, do not use jam jars," she said.
"Why go to the expense of having something fancy made when the jars did what they were supposed to do?
"There was also a Schweppes bottle, which, I think it was a bit of a joke on Father Kevin's part - he had lottery tickets rolled up inside it.
"That was quite entertaining to open that and see he had a good sense of humour," Doocey said.
"We think possibly it might be that relics became almost uncool.
"So he put them in a steel box, what we call a tabernacle, and he buried them beneath the side chapel and he'd written a note to say they were buried...it was just a matter of finding them."
The relics were collected by the first bishop of Christchurch, Bishop Grimes, who held the position from 1887-1915.
He picked them up on trips to the Vatican, and had an extensive collection - some are believed to date back to the medieval times, Doocey said.
"Everybody had their favourite saints, so he really did have a widespread selection."
The relics have been extensively studied and arranged into the 'Saints in Coffee Jars' exhibition, which will open on Waitangi Day at the Pūmanawa Art Gallery in Christchurch's Arts Centre.
It runs until Saturday, February 10. And for those who cannot make it in person, a website will also be launched on Tuesday to coincide with the exhibition's opening.