Would we be able to replicate that? If we added other brands and a homemade burger to the mix, which one would decay first and which would decay the least?
I was surprised by the results myself. Firstly, the McDonald's burger and fries did decay, and actually the burger decayed most between the two other fast food chain samples of Wendy's and Burger King. Burger King's burger decayed last and the least, but their fries deteriorated first.
Of course, the homemade version became disgusting right away and showed the most in mold growth. Remember, anything that bacteria will eat is organic and "real". You would want to eat something that breaks down and decomposes.
When I was frying up the homemade burger, it smelled appalling. Sautéing onions and vegetables smells ten times better than fatty ground chuck. The fat that came off of that patty also was a reminder of how artery clogging that stuff is and why I stay away.
A creepy issue with the McDonald's food was that the mold growing on it was somewhat different than the others. The fries were very green and it was the only item that grew black mold. I suppose if we conducted a more advanced experiment, we could determine the types of mold and why some grow and others don't. Probably depends on the materials of which they grow.
I had to end the experiment at 12 days. Couldn't take it anymore and didn't want to risk letting loose those mold spores too much. Especially the black mold, which I am allergic to.
Here are the results after 12 days:
Burger King Whopper meal day 12
Home prepared ground chuck burger and baked fries at day 12.
McDonald's Quarter Pounder and fries at day 12.
Wendy's Single meal day 12.
I guess if I were to conduct this again to try and replicate those that left the items in the bag, it may have turned out differently than ours being housed in sealed containers. I just didn't want to leave food out in a bag. This was gross enough.
So if you intend to clog your arteries with a burger, make it at home. If you prefer a fast food heart attack, eat Burger King fries and a McDonald's Quarter Pounder.