Students’ Germ Test On Bread Reveals Disgusting Results

by : Julia Banim on : 18 Dec 2019 13:32
Students' Germ Test On Bread Reveals Disgusting ResultsStudents' Germ Test On Bread Reveals Disgusting ResultsJaralee Annice Metcalf/Twitter

Without sounding like your mum, you should always, always wash your hands after nipping to the loo. Not only is failing to do so extremely gross and inconsiderate, it also puts the health of others at risk.


Unwashed hands can lead to the spreading of the common cold – already so widespread at this time of year – as well as bouts of food poisoning and other more serious illnesses.

Admittedly, it can sometimes be difficult to visualise the effect germs can have with the human eye alone. But don’t worry, I’m here with a story guaranteed to put you off your lunchtime sandwich…

Bread germ experimentBread germ experimentJaralee Annice Metcalf/Twitter

After coming across a grimly fascinating science experiment on the C.S. Mott Children’s Hospital website, behavioral specialist Jaralee Annice Metcalf decided to teach her pupils an important lesson about health and hygiene to coincide with flu season.


The class took five slices of plain white bread for their experiment, with each slice used to demonstrate how germs could develop under different circumstances.

The pupils all touched one slice of bread after washing their hands with soap and warm water, and touched another after cleaning their hands with hand sanitiser.

One slice was left untouched, while another was touched with unwashed hands. The fifth – particularly yucky – slice was rubbed all over the classroom Chromebooks.

Bread germ experimentBread germ experimentJaralee Annice Metcalf/Twitter

The slices were each placed in individual clear plastic bags and labelled accordingly. Due to preservatives, the results took around three to four weeks to become clear. And boy, will this experiment get you scrubbing those palms.

The ‘fresh and untouched’ slice still looked fit for a sarnie, while the ‘soap and water’ slice would probably still do for toast at a push. However, the results are far more stomach-churning when it comes to the other – less sanitary – slices.

The ‘hand sanitiser’ slice was fit only for the bin, while the ‘dirty hands’ one appeared to have developed an entire ecosystem of its own, complete with germ airports and warring governments. And the less said about the ‘wiped on chromebooks’ slice the better.

Bread germ experimentBread germ experimentJaralee Annice Metcalf/Twitter

Metcalf shared photographs of her findings on Facebook along with the following plea:

As somebody who is sick and tired of being sick and tired of being sick and tired. Wash your hands! Remind your kids to wash their hands! And hand sanitizer is not an alternative to washing hands!! At all! This is so DISGUSTING!!!

The alarming post has since been shared more than 17,000 times, with plenty of grown-ups learning from this clever classroom experiment.

Reflecting on the amazing response she has since had, Metcalf told UNILAD:

So we found this particular one on Mystery Science and decided we wanted to try it out. Honestly there has been a lot of sickness. So many staff and students out. My family especially has been sick. My 8- month-old son and my husband!

And of course myself. So we wanted to show the kids how fast germs can spread and how detrimental hand washing is to our health. Neither the children or adults expected the results! They were shocking and enlightening. We have definitely upped our hygiene habits around the classroom!

I am glad there were not too many negative reaction. Most are quite positive and it makes it enjoyable to read! Whether they’ve done the experiment themselves or want to do it, I’m glad we’ve inspired some people!

We did a science project in class this last month as flu season was starting. We took fresh bread and touched it. We did…

Posted by Jaralee Annice Metcalf on Thursday, December 5, 2019

Dr Terri Stillwell, MD, Associate Hospital Epidemiologist at Mott Children’s Hospital, has made the following comments regarding this experiment:

You should wash your hands before, during, and after preparing food. Also wash before you eat, after using the restroom, after blowing your nose, after touching animals, and any time your hands appear dirty.

Dr Stillwell added:

The scrubbing part of washing your hands is important. It’s the combination of the friction of rubbing your hands together along with the soap that really gets them clean. Take your time and sing or hum the Happy Birthday song twice.

If soap isn’t available, Dr Stillwell advises using an alcohol-based hand sanitiser, which you should rub all over your hands before allowing to dry.


Right. So there’s me avoiding the work bread bin for the foreseeable…

If you have a story you want to tell, send it to UNILAD via [email protected]

Julia Banim

Jules studied English Literature with Creative Writing at Lancaster University before earning her masters in International Relations at Leiden University in The Netherlands (Hoi!). She then trained as a journalist through News Associates in Manchester. Jules has previously worked as a mental health blogger, copywriter and freelancer for various publications.

Topics: Science, Bread Test, C.S. Mott Children's Hospital, Germ Test, Health, Mould, Wash Hands


C.S. Mott Children's Hospital and 1 other
  1. C.S. Mott Children's Hospital

    How Clean Are Your Hands?

  2. Jaralee Annice Metcalf/Facebook

    Jaralee Annice Metcalf/Facebook