An 8-year-old girl managed to bust one of the biggest myths about McDonald's burgers in just 3 weeks

The burgers on June 22 – the Macca’s cheeseburger is on the left. Photo: Lulu Thomsen

May 27 was a big day for Lulu Thomsen, my 8-year-old daughter. Her mum took her to McDonald’s, along with her 10-year-old brother, for the first time.

But they didn’t visit Maccas to eat. They were there in the name of science. Lulu bought a cheeseburger for a school project and brought it home to conduct a science experiment based on the common tale that McDonald’s burgers never rot.

Numerous stories abound of burgers lasting for up to 14 years with no sign of decay.

There’s even the burger and chips in Iceland, on permanent webcam, from when the country’s last McDonald’s closed in 2009.

Based on that oft-told tale, Lulu wanted to conduct her own experiment, with the hypothesis that there are so many preservatives in a Maccas burger, it won’t rot.

At dinner the following night, dad knocked up an extra home-made burger, which she used as her control burger, to compare with the McDonald’s version.

It took her less than a month to prove the “no rot” idea is little more than a myth, albeit an all-pervasive one.

By June 10 she found mould growing on one corner of the patty and bun.

The secret behind what happened has already been explained on Business Insider by Dr Keith Warriner, who said “the microbes that cause rotting are a lot like ourselves, in that they need water, nutrients, warmth and time to grow. If we take one or more of these elements away, then microbes cannot grow or spoil food.”

June 10 – mould appears. Photo: Lulu Thomsen

Lulu didn’t realise it at the time, but by putting her burger in her mum’s airtight cake container and sticking it on top of the fridge, she was creating the perfect environment for the bacteria to party all over the burger. The moisture was retained, rather than drying out in the natural air, and it was warm.

When she checked in again on June 22, the McDonald’s burger was totally covered in gun-metal grey moulds. The home-made version too. And they stank.

Lulu presented her findings to her grade 3 class this week, proving that McDonald’s burgers do indeed rot.

And after what she’s seen and smelled, Lulu has even less interest in ever going to McDonald’s again. She now says she wants to be a scientist. Or popstar. I told her to aim for both.

Her mother is hoping she’ll get a replacement cake container soon.

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