Science: Growing Bacteria
Everyday Unschooling / Science / Unschooling

Everyday Unschooling: Growing Bacteria

Science: Growing Bacteria

Everyone is big on experimenting here at the moment! Miss 3 is always asking to ‘do experiments’. Which for her means grabbing lots of supplies from the kitchen and mixing up ‘potions’. She loves it!

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Recently, Miss 6 was looking through a science book we have for inspiration for her next experiment. She has always been interested in fungi and when we go for bush walks likes to point out all the different coloured fungi she can find. So, the chapter on bacteria, mould, and fungus caught her eye. She wanted to grow bacteria!

This was something we didn’t have the supplies for and couldn’t do immediately but we ordered some petri dishes and went shopping for the ingredients to make our agar.

When the petri dishes arrived in the mail, everyone was keen to be involved in the experiment. The older two girls cooked the agar and I poured it into the dishes for them. Then they, along with Miss 3, made a list of all the things they wanted to test.

When the agar was set, they got to work!Science: Growing Bacteria

They tested: the fridge, a hand, the fish tank, the door handle, the hedge, a cough, the toilet, a bike, their lips, a tree, a foot, the terrarium, their nose, and their ear. We did mean to leave one as a control but totally forgot in the excitement of swabbing all the things!

Science: Growing Bacteria

All the dishes were labelled and sealed with sticky tape so they were safe and could not be opened.

Science: Growing Bacteria

Science: Growing Bacteria

Next, the girls each made predictions about which samples they thought would grow the most bacteria, and which would grow the least.

Miss 8 thought that her cough, nose, and ear would grow the most, while the trees and terrarium would grow the least. Miss 6 predicted her bike, the cough, and the toilet would grow the most, and the fridge the least. Miss 3 thought that the trees, and her ear would grow the most, and that her lips would grow the least.

Science: Growing Bacteria

We left them on the shelf, next to the microscope, and they wondered how long it would take to see anything.

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Not long! When they checked on them first thing the next morning some bacteria had already started to grow. It happened so fast!

Science: Growing Bacteria

By that afternoon there was lots more bacteria, and soon after mould had started to grow.

Science: Growing Bacteria

Looking at all the things growing under the microscope was fascinating! We could see similarities and differences between ones that were from human bodies, and ones from the trees.

Science: Growing Bacteria

Almost a week later and things were looking pretty mouldy! We decided to call an end to the experiment. Time to work out which samples grew the most. We grouped them into piles with lots of bacteria, least bacteria, and somewhere in the middle.

Science: Growing Bacteria

Together the girls decided on which were the winners, and wrote down their findings.

Science: Growing Bacteria

It looked like the terrarium and the bike grew the most, and the cough and door grew the least! There was lots of discussion about who had guessed right, and what ones they were surprised about. They thought a cough would have grown more bacteria.

Science: Growing Bacteria

We printed out the photos of the bacteria under the microscope to look at and keep, and Miss 6 did some painting inspired by them.

Science: Growing Bacteria

Miss 8 also reminded us we had this book, ‘Tiny: The Invisible World of Microbes‘, which we read. It’s been a long time favourite because it explains the amazing jobs such tiny bacteria do in our world and is fascinating to the kids.

The girls also shared their excitement about the experiment with their friends and ended up sending the bacteria pictures to one of their friends to look at too.

It was such a fun experiment!

Have you ever grown bacteria? Not something I ever thought I’d be excited about, ha! The surprising world of unschooling.


The book Miss 6 found this experiment in is The Curious Kids Science Book. It’s the only science experiment book I recommend, as it’s not so much about following directions, but instead making the experiment your own, and figuring out your own way to test your theories. There are more instructions on how to make the agar and collect the samples in the book, as well as lots more information for the kids on what bacteria, mould, and fungus actually are. You can also read more about this book in a previous post, here.


This post is part of a series of posts documenting our day-to-day life as an unschooling family. Sometimes it’s hard to picture what unschooling looks like, so here I hope to provide a little window into the kid’s life and learning. This is just an example of what unschooling can look like, but it’s very different for each family. It’s not designed to be read as an ‘activity idea’ that you can set up for your child, but an account of four inspired young people who have the freedom to learn how and what they desire.

Science: Growing Bacteria


November 12, 2017 at 4:14 pm

A very inspiring post, thank you. My kids love examining the micro world with their microscope. May I ask how you took photos of the bacteria under the microscope?

November 12, 2017 at 8:00 pm

Such a fun experiment! I remember years ago my oldest looked at her own blood under the microscope and found it so fascinating. Then she compared breast milk to pasteurized cow’s milk. That was especially fascinating, as the breast milk still had living, moving organisms the way the blood did, as opposed to the pasteurized milk where everything was dead. We took pictures through the eyepiece of the microscope too, and she also took video of the breast milk in action. 🙂

November 21, 2017 at 11:51 pm

Would you recommend your microscope? If so, where is it from please, Id like to purchase an easy to use microscope for our family experiments?
Thanks Sara,

March 11, 2018 at 8:48 am

I absolutely love this post!! My mum did similar experiments with our microscope at home when I was growing up. I’m so excited to be able to share this with my daughter!
Thank you for sharing these snapshots of your days.

Rita Sanders
March 26, 2020 at 1:35 am

It’s really awesome that you just grew bacteria in your own home! I’m curious though, what is agar? If I were to do this with my kids, I’d need to know.

March 31, 2021 at 7:28 am

How did you make your agar?

June 4, 2024 at 12:13 pm

Hi, did you keep the Pietri dishes after the experiment? If so, how did you dispose of the content and sterilize the glass?

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