Big Mac That Remains Intact Without Rotting Even After 100 Days... Differences from Other Burgers [Hamburger Rotting Experiment]⑥

Experiment on Decay of Six Major Brand Burgers
Spread of Mold and Evaporation of Moisture
Five Guys Burger Becomes Unrecognizable
No Mold Found on Big Mac After 100 Days in Refrigerator

Asia Economy's hamburger decay experiment, which began on October 7 last year, has surpassed the year mark and reached its 100th day as of the 15th. To verify the truth behind the rumor circulating on YouTube and other social networking services (SNS) that "hamburgers do not rot," the main products of six popular burger franchises available on the market (McDonald's, Mom's Touch, Lotteria, Burger King, KFC, and Five Guys) were selected as the test subjects. After 100 days of observation, these products left at room temperature showed varying degrees of mold growth on the buns and patties, indicating ongoing decay.

Big Mac stored in the refrigerator for 100 days. Photo by Jinhyung Kang

The speed of burger decay over 100 days ranked as follows: ① Five Guys Bacon Cheeseburger → ② Mom's Touch Cyburger → ③ KFC Zinger Burger → ④ Burger King Whopper → ⑤ Lotteria Bulgogi Burger → ⑥ McDonald's Big Mac.

Notably, the top four burgers?from Five Guys Bacon Cheeseburger to Burger King Whopper?had their top buns covered with dark green and yellow mold after 100 days. Among these, the Five Guys Bacon Cheeseburger developed cloud-shaped mold to the extent that, except for some melted cheese, the contents were indistinguishable. The Mom's Touch Cyburger also showed severe distortion of the patty and vegetables, except for the top and bottom buns.

Additionally, the KFC Zinger Burger and Burger King Whopper showed extensive mold growth on the top buns, and the patties made of beef and chicken were reduced to mere shapes, with no trace of their original appearance. However, most test samples appeared to have temporarily halted decay, looking dried out. The moisture that had condensed inside the plastic containers also disappeared.

The Lotteria Bulgogi Burger, which decayed relatively slowly, developed a white, long mold band on the bottom bun, and the patty hardened to the point where no moisture could be felt.

100th Day of Hamburger Decay Experiment (clockwise from top left) Five Guys Bacon Cheeseburger, Mom's Touch Ssaiburger, KFC Zinger Burger, Burger King Whopper. Photo by Jinhyung Kang

The McDonald's Big Mac, which showed the slowest changes among the test subjects, exhibited no significant external changes even after 100 days, except for some contents like vegetables and sauce spilling around the bun. Although the overall size of the burger slightly decreased due to moisture evaporation from the patties and ingredients, the decay appeared to have stopped.

All six hamburgers underwent decay experiments under the same conditions over the past 100 days. However, the decay rates varied significantly, which seems to be due to differences in moisture content within the burger ingredients. The Five Guys Bacon Cheeseburger, which decayed the fastest, contained relatively many moisture-rich vegetables such as thick beef patties, tomatoes, onions, lettuce, and saut?ed mushrooms. According to the burger companies, the Mom's Touch Cyburger and KFC Zinger Burger use fried chicken patties, and the frying process traps moisture in the chicken, accelerating decay.

100th Day of Hamburger Rotting Experiment: McDonald's Big Mac (left) and Lotteria Bulgogi Burger. Photo by Jinhyung Kang

On the other hand, the McDonald's Big Mac and Lotteria Bulgogi Burger contained lettuce but had fewer vegetables compared to the other test subjects. Their patties were mostly made of beef, which has lower moisture content.

Previously, Professor Ha Sang-do of Chung-Ang University's Department of Food Engineering presented at the 2015 Public Health Comprehensive Academic Conference that although the onset of decay varied among fast-food hamburger brands, all showed visible mold growth within 3 to 8 weeks. At that time, Professor Ha explained, "Burgers that decayed more slowly without preservatives in the buns likely used fresh flour as the main ingredient, and the higher baking temperature resulted in lower initial bacterial counts and general bacterial contamination compared to other brands' buns."

Meanwhile, to observe changes in the Big Mac, which frequently appears in overseas YouTube experiments, under room temperature and refrigerated storage, additional products were stored in a refrigerator for 100 days. Upon inspection, the product's appearance showed little difference from the time of purchase. The double-layered patties, as well as ingredients like lettuce and cheese, mostly retained their original form. No mold was found on the buns or the entire product. There was also no significant change in odor that would indicate decay.

Asia Economy plans to continue observing under the same conditions in the new year to determine which hamburger visually lasts the longest without rotting.