But the sandwiches basically turned into lab petri dishes…
Youtube user DebunkerSam posted a video experiment of what happens to McDonald’s sandwiches and fries over the course of 10 weeks. As you can imagine, the footage is pretty repulsive, so watching it right before or after a meal is not advised.
It was decided that, in addition to McDonald’s fries, the following sandwiches would take part in the experiment: the Chicken McGrill, the Fillet-o-Fish, the Quarter Pounder, and of course, the Big Mac.
To give the experiment an interesting spin, the experimenter also purchased a regular burger and fries from a non-fast food chain to compare the decomposition processes. Unsurprisingly, in two weeks, the french fries from the non-fast food restaurant were blackened with mold, and the burger had also grown mold, completely humidifying the glass container.
The McDonald’s sandwiches all fared differently — the Chicken McGrill had clear patches of black mold and the Quarter Pounder had a mysterious white fuzz. The Fillet-o-Fish had just started to mold, but the Bic Mac remained unscathed. As did the McDonald’s fries. The skinny, yellowish sticks stayed looking as familiar as ever.
The experimenters check back in on the burgers and fries at three weeks, five weeks, and eight weeks before the grand finale of 10 weeks. After three weeks, the video reveals that the interns were so disgusted by the regular burger and fries that they had to be thrown out, but all of the McDonald’s products were fair game.
As the video shows, the sandwiches certainly didn’t look pretty during the experiment’s concluding weeks. However, even at the 10 week mark, the fries showed no signs of mold — it looked like the fries were maybe a day old at most.
How is this possible? It has a lot to do with the dehydration process of the fries. Without moisture, mold can’t grow, and McDonald’s french fries are soaked in hydrogenated oil — saturated fat which increases shelf life and maintains flavor. As the french fries cool, they’re essentially sealed by the hardening saturated fat, which in turn seals off moisture.
Similar to the reasons why McDonald’s burgers also seem to take longer than others to rot, the key to the immortal McDonald’s food mystery appears to hinge on moisture levels, as reported by IFLScience. Even McDonald’s took it upon itself to address the issue: “Food needs moisture in the air for mold to form. Without it, food will simply dry out — sort of like bread left out on a counter overnight to make croutons for stuffing.”
But just because there’s a logical explanation for McDonald’s seemingly unrottable food doesn’t mean it’s time to hit the drive-through and load up on Big Macs and fries. The majority of McDonald’s sandwiches account for over half of your daily sodium value, and a medium fries alone are a quarter of the fat you should consume for an entire day. The World Health Organization recommends 25 grams of sugar a day, and a large chocolate shake from McDonald’s contains a whopping 120 grams of sugar.
When it comes to fast food: moderation.
Don’t believe that McDonald’s fries remain unscathed after 10 weeks? See the video experiment for yourself: