"The reason fruitcake, or any cake for that matter, goes stale, is because it appears to lose its moisture," said physicist Peter Barham of the University of Bristol in England, author of "The Science of Cooking." But the moisture is not actually lost -- the starch in the cake has simply absorbed it.

The problem, Barham explained, is the molecules in the starchy flour of the cake are trying to regain the ordered form they had when they were in wheat. Since the starch is incapable of making that transformation, it instead does the next best thing and hijacks water from the cake to form small crystals. With all the water caught up in these starch crystals, the cake tastes dry and is tougher to digest.

Physics has the answers for what you need to do to resuscitate the cake. "You just need to melt the starch crystals," Barham said.

The cake should be wrapped in aluminum foil to prevent any moisture from escaping and slowly warmed in an oven to 200 degrees. This melts the crystals, releases the water and refreshes the dry fruitcake.

"While starch begins to lose its crystalline character at 130 degrees, if you have the oven set at that temperature, it's going to melt, but at a much slower speed. Two hundred degrees is still cool, but it will rehydrate the cake a lot faster," explained food science expert Harold McGee in Palo Alto, Calif., author of "On Food and Cooking: The Science and Lore of the Kitchen."

Not that there was necessarily anything wrong with dry fruitcake, McGee quipped.

"I'd always been under the illusion that one of the purposes of fruitcake was to encourage the consumption of fluids, and a dry fruitcake is a better excuse to drink and put butter on it," McGee said in an interview with United Press International.

For those concerned about the taste of particularly old fruitcake, Barham asserted that fruitcakes actually get better the longer they sit. "The dried fruits in the cake can actually age much like wine ages over time," he contended.

Chemicals known as tannins present in the fruit of the cake -- which are also found in grapes and are part of the aging process in red wine -- seep into the cake, chemically changing it to create intense and distinct flavor compounds. The longer the cake sits, he said, the more varied and intense the flavors become.

While it is true that fruitcake aficionados may prepare their concoctions weeks or months ahead of time for the holidays, McGee said more complicated, intense fruitcake flavors may not necessarily be the best of ideas.

"It depends on what flavor you're starting with," McGee said. "The candied fruits are high in sugar, which are going to caramelize over time and tend to actually make flavors less complicated, because the caramel tends to override the other flavors."

"In time fruitcakes don't just get dry, they get stale," he added. "And then they develop particular aroma characteristics that we don't find all that pleasant."