McDonald's/FacebookApril 10, 2010 was day one of New York photographer Sally Davies' "Happy Meal Project," which documented what happens to fast food if left unrefrigerated under a glass case. Five months into the experiment, the Mickey D's meal still looked edible while KFC fries bought and stored on the same day were white and furry with mold. As of January 2016, the hamburger and fries didn't noticeably disintegrate.
Marion Nestle, chair of NYU's food studies program, told Salon that McDonald's would have to use "a lot of sodium propionate to prevent bacterial or mold growth." Dr. Keith Warriner, a Canadian food scientist, explained that another reason might be due to the lack of moisture in the patty and bun during the steaming and toasting preparation. Without moisture or high humidity - ideal conditions for microbe growth - the burger dries out rather than rots. Even with a scientific explanation, it sounds so icky just thinking about it that we want a 7-day tea cleanse, stat!