A loooong time, apparently.
http://www.cnn.com/2003/US/12/22/offbeat.fruitcake.ap/index.htmlLeno to taste 'fossilized' fruitcake
TECUMSEH, Michigan (AP) --A fruitcake that is an estimated 125 years old -- an artifact of holiday cheer -- is expected to make a tasty debut of sorts when it's introduced on national TV.
Morgan Ford, 83, of Tecumseh, is taking his great-grandmother Fidelia Bates' fruitcake to Burbank, California, to share a piece with Jay Leno on Tuesday's "The Tonight Show with Jay Leno."
The cake rests in a glass bowl, covered by a glass top. A large raisin and what might be a clove are visible among the brown mass -- Ford says it's fossilized -- that emits a pleasant odor of spices.
Its baker died in Berkey, Ohio, in 1879 and the cake remained untouched for 85 years.
Not much is known about the origin of the cake; even the recipe is lost.
"I don't think my dad knew anything more about it than I do now," Ford said.
Ford intends to pass along the fruitcake to his son, James Ford, of Tecumseh.
"I guess I don't have anything else that's a family heirloom," James Ford said. "It's history. I think my dad gets a little more fun out of it than I do."