[Rotting Hamburger] ① Experiment 'Start'... Which Brand Survived for 7 Days?

Six Major Burger Brands Including McDonald's and Mom's Touch
Mold Found in Mom's Touch, KFC, and Five Guys
No Exterior Issues in McDonald's, Burger King, and Lotteria

The top row features Five Guys, Mom's Touch, and KFC.
The bottom row features Lotteria, McDonald's, and Burger King.

American fast-food franchise Burger King showcased an advertisement in 2020 featuring its flagship product, the Whopper hamburger, covered in mold. With the slogan "The beauty of no artificial preservatives," the ad displayed the natural decay process of a freshly made Whopper over 34 days, successfully delivering a powerful message about eliminating preservatives and other artificial additives from hamburgers.

The "non-decaying hamburger" is a recurring topic in the media from time to time. In 2020, a man living in Utah, USA, discovered a McDonald's hamburger he bought in 1999 for 79 cents in the pocket of a jacket he hadn't worn for a long time. He said, "The pickles, ketchup, and onions had dried up, but the bun and patty looked as if they were freshly cooked, at least after the iPhone was invented (2007)."

There have been people who conducted experiments themselves to verify the rumor that hamburgers do not rot. H?rður Sm?rason, living in Iceland, bought a cheeseburger on October 31, 2009, when McDonald's decided to close due to the financial crisis, and kept it at home for three years. During that time, the cheeseburger did not rot, and he held an exhibition featuring this burger at the National Museum of Iceland. Later, the burger was displayed at a hotel in Iceland run by a friend. Sm?rason described the condition of the cheeseburger he last checked as "fresh as always."

Hamburger Experiment Day 1. Photo by Dongju Yoon doso7@

Hamburgers don't rot? To verify this long-standing rumor, the Asia Economy Food & Beverage Team conducted an experiment themselves. The subjects were signature burgers from six hamburger chains sold on the market: McDonald's, Mom's Touch, Lotteria, Burger King, KFC, and Five Guys.

On Monday the 7th, they were purchased at the same time, unwrapped, and stored in transparent containers. The temperature in the Asia Economy studio in Chodong, Jung-gu, Seoul, where the boxes were placed, was between 20-25 degrees Celsius, and humidity was around 50-75%. Due to conditions, the observation focused on external changes such as color and mold.

As of the check on the 14th, several hamburgers had started to rot within a week. Changes appeared in three out of the six. Some hamburgers that looked edible as of Friday afternoon on the 11th showed mold when checked after arriving at work on Monday. These were Mom's Touch's Cyburger, KFC's Zinger Burger, and Five Guys' Bacon Cheeseburger.

From the left: Five Guys, Mom's Touch, KFC

The most decayed hamburger was Five Guys' Bacon Cheeseburger. Large white mold patches began to appear not only on the bun but also on the beef patty and tomato. There was no mold on the melted cheese. Mom's Touch's Cyburger showed mold on the bun, chicken patty, and lettuce. KFC's Zinger Burger had similar mold on the bun and chicken patty.

The remaining McDonald's Big Mac, Lotteria Bulgogi Burger, and Burger King's Whopper survived externally intact. However, as the moisture in the lettuce evaporated, the bun shrank significantly as if it had swallowed the beef patty and vegetables. In the Big Mac, which consists of three buns and two beef patties, the lettuce was barely visible and appeared dried out.

From the left, Lotteria, McDonald's, Burger King

The hamburger decay experiment will continue until all hamburgers rot. Since the types and amounts of moisture-containing ingredients vary in each hamburger, it is difficult to conclude that a particular brand lasts longer or shorter. However, through this experiment, it is expected to identify which brand’s hamburger, under the same temperature and humidity conditions, appears to be the longest-lasting "phoenix" hamburger in terms of external appearance.