Need another reason to swear off McDonald's burgers? How about the preservatives. They preserve a little longer than you'd think. 

David Whipple learned just how long when he pulled one out of a coat pocket he hadn't checked in two years -- and then kept it to see how it would develop.

The St. George, Utah, resident ordered his burger with a pickle, mustard and ketchup on July 7, 1999, a time when he was struggling with his weight. Instead of eating it, he decided to use the burger for a project he was doing about enzymatic action with other people who were advocating weight loss.

At a meeting of the group a month later, Whipple showed the hamburger, bun and pickle, "which was just starting to disintegrate," Whipple wrote in the blog he set up about the burger experiment, reports TV station KSL. "There was no decomposition to the meat or bun, nor any mold, fungus or smell. It had no bad odor at all.”

Whipple says he put the burger in a jacket pocket after the meeting and completely forgot about it until about two years later, when he discovered it pretty much the way he'd last seen it. Now, 12 years later, you could say it's aged pretty well -- or not.

Whipple's story attracted the attention of the Emmy Award-winning television program “TV Doctors,” which provides discussions about various health topics. And Tuesday the burger went viral.

"It was purely a fluke about hanging on to it," Whipple said in an interview with ksl.com

He has never refrigerated the burger and does not understand how it has remained in relatively good condition.

"That's the million-dollar question. They dig up things in King Tut's tomb," Whipple said. "It's going to take a smarter person than I am to figure [it] out."