Fully Bloomed Mold Flowers... Two Types Including McDonald's Remained Intact [Rotting Hamburger]②

Six Burger Brand Signature Products Tested for Two Weeks
Five Guys Shows Fastest Spoilage
Mam's Touch, KFC, Burger King Also Show Visible Changes
McDonald's and Lotteria Maintain Appearance

The Asia Economy Food & Beverage Team has been observing the daily decay status of flagship burger franchise products sold on the market for two weeks. The signature products from six companies?McDonald's, Mom's Touch, Lotteria, Burger King, KFC, and Five Guys?have begun to show noticeable changes in appearance. Although the degree varies by product, there has been an increase in burgers with buns and patties covered in mold, and several test subjects have become difficult to recognize in terms of their vegetable components.

On the 22nd, marking the third week and the fifteenth day since the experiment began, the product showing the most severe decay to the naked eye was Five Guys' Bacon Cheeseburger. This product first showed visible changes on the 14th, one week in, with white mold appearing on the bun, beef patty, and tomato, and the cheese melting.

After another eight days, the mold on the top of the bun had doubled in number and grown significantly larger than the previous week. Yellow and dark blue spots formed on top of the white mold, creating a mushroom-like shape. Blue mold also spread over a wide area where the patty and bun met, and the container holding the product was filled with moisture, likely generated during the decay process.

On the 15th day of observation, the Five Guys Bacon Cheeseburger (left) and the KFC Zinger Burger condition. Visually, the mold size has increased and the areas where it has spread have expanded. Photo by Dongju Yoon doso7@

Mold also became noticeable on KFC's Zinger Burger and Mom's Touch's Cyburger, both of which use chicken patties, after two weeks. On the Zinger Burger, a single white mold spot appeared on the end of the crispy chicken after one week, and by the fifteenth day, extensive mold had developed in several areas, including where the bun, vegetables, and patty met. The overall appearance did not change much from when purchased, but the visible vegetables had shrunk, and moisture from decay was present.

The Cyburger developed two small mold spots along the side of the bun after one week, and by the fifteenth day, dark blue mold had spread to the patty, increasing in size. The inside of the test container was filled with moisture to the extent that droplets ran down the walls.

Burger King's Whopper, which showed little change during the first week of the experiment, developed small white mold spots on the bottom of the bun on the eighth day, the 15th. Another week later, the mold had expanded enough to cover the top of the bun. No other visible changes such as evaporation of moisture from the patty or vegetables or size reduction were observed.

Observation on the 15th day: Mom's Touch Cyburger (left) and Burger King Whopper condition. Large and small mold spots are scattered around the bun and patty. Photo by Dongju Yoon doso7@

Previously, Burger King released a 45-second global advertisement on its official YouTube channel in 2020, showing a Whopper covered in mold after 34 days. The ad highlighted the product as made from eco-friendly ingredients with the English copy "The beauty of no artificial preservatives." In the video, after 34 days, the entire burger?including the bun, vegetables, and patty?was covered in dark blue mold. The moisture had completely evaporated, and the burger had shrunk compared to when freshly made. Although experimental conditions differ, we plan to observe whether the Whopper's decay progresses to a similar level over the next 20 days based on our observations.

Observation on the 15th day: Condition of McDonald's Big Mac (left) and Lotteria Bulgogi Burger. Compared to other test groups, decay is slower, and mold appears only slightly on the bottom of the bun, generally maintaining the initial appearance of the experiment. Photo by Dongju Yoon doso7@

McDonald's Big Mac and Lotteria's Bulgogi Burger showed much slower changes in appearance over the fifteen days compared to other test groups. On the eighth day of the experiment, the Big Mac showed a small white mold spot about the size of a fingernail on the bottom patty, but its overall shape remained almost identical to the start. On the same day, the Bulgogi Burger developed black mold on the bottom bun, which spread sideways, but the degree of decay was less severe compared to other burgers.

The temperature at the Asia Economy studio in Chodong, Jung-gu, Seoul, where the observations were conducted during the second week, averaged 24.4 degrees Celsius with humidity ranging from 43% to 65%. Asia Economy will continue to observe under the same temperature and humidity conditions to determine which burger remains unspoiled the longest based on appearance.