• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Menu
  • Science Experiments For Kids
  • Science Fair Projects
  • Preschool Science
  • Science Facts
  • Printable Experiments
  • Science Sparks Books
  • Science Questions
  • Contact Me
Science Experiments for Kids
Menu
  • STEM Challenges
  • Early Years Science
    • Preschool Science
    • Sensory and Messy Play
    • Understanding of the World
    • Pirate Science Experiments
  • Primary Science
    • Baking Soda Experiments
    • Candy Experiments
    • Biology
    • Climate Change for Kids
    • Coding for Kids
    • Chemistry
    • Electricity for Kids
    • Magic Science Experiments
    • Harry Potter Experiments
    • Human Body Science
    • Air Pressure Experiments
    • Life Cycles
    • LEGO Science Experiments
    • Kitchen Science
    • Famous Scientists
    • Forces and Motion
    • Science Sparks Snippets
    • Key Stage 1 Science
      • Animals
      • Everyday Materials
      • Plants
      • Coding Activities
      • Humans and Health
      • Fine Motor skills
      • Science and Literacy
    • Key Stage 2 Science
      • Animals, Including Humans
      • Electricity
      • Light
      • Plants
      • Materials and their Properties
  • Key Stage 3
  • Holiday Science
    • Christmas Science
    • Halloween Science
    • Easter Science
  • Storybook Themed Science Experiments
  • Wonderful Women in STEM
menu icon
go to homepage
search icon
Homepage link
  • FREE Experiments
  • Science for Kids
    • Kitchen Science
    • Climate Change
    • Egg Experiments
    • Fairy Tale Science
    • Edible Science
    • Human Health
    • Chemistry
    • Inspirational Women
    • Forces and Motion
  • Science Fair Projects
  • STEM Challenges
  • Science Sparks Books
  • Contact Science Sparks
    • Email
    • Facebook
    • Instagram
    • Twitter
    • YouTube
  • ×

    Home » Key Stage 2 Science » Why Does Food Rot?

    Why Does Food Rot?

    March 5, 2012 By Emma Vanstone 13 Comments

    Why does food rot? Have you ever noticed that if you leave an apple (or any fruit ) for too long it starts to rot or decay?

    Mouldy tomatoes
    Rotting tomatoes

    Why does food rot?

    Food rots because micro-organisms such as bacteria, yeasts and fungi feed on the fruit and break it down. Have you also noticed that keeping fruit and vegetables in a fridge makes them last longer? This is because the cold slows down the growth and reproduction of micro organisms slowing the decay.

    Rotting mouldy foods on a chopping board
    Mouldy food on a chopping board

    How to preserve apples

    Today we are looking at other ways to try to preserve apples.

    preserve apple by keeping them in vinegar
    apples in vinegar, lemon juice and salt water

    What you need for an apple rotting experiment

    • One apple
    • 4 containers
    • lemon juice
    • vinegar
    • salt water ( 1 tablespoon salt dissolved in hot water )

    Apple rotting investigation instructions

    • Cut the apple into 4 even pieces.
    • Place a segment of apple into each container.
    • Cover each apple with the same amount of either lemon juice, vinegar or salt water. Leave one just exposed to the air     ( this is the control ).
    • Leave untouched for about a week in a cool place and observe the differences.

    Apple rotting investigation results

    Control Apple – you can see this has started to shrivel up, but there is not much evidence of mould.

    Apple rotting investigation - results - shrivelled up apple
    Mouldy apple left in the air

    Salt and vinegar ( vinegar is at the front )

    Apple rotting experiment - apples left in vinegar
    apple preserved in salt and vinegar

    Lemon Juice

    Apples left in lemon juice
    apple preserved in lemon juice

    How can you stop food rotting?

    There are many mechanisms of preserving food, all slow or stop the activity of the micro-organisms which make the fruit decay.

    As well as refrigeration, you can freeze, can or pickle foods to preserve them.

    You can see from the photo’s that in our investigation the apple segment in the salt is the best preserved. This is because salt draws the moisture out of the food so the micro-organisms do not thrive and cannot reproduce as fast as they can in the other conditions.

    The vinegar did prevent mould growing, this is because vinegar has anti-microbial properties. This means the vinegar inhibits or kills the microorganisms.

    You can see that the lemon juice shows evidence of mould. This could be because the micro-organisms have flourished in the sugary environment.

    More food preservation ideas

    Can you think of other things to try? What about bicarbonate of soda? Or trying different fruits?

    The Free Range Life has some great ideas for preserving peppers you could test too!

    More kitchen science experiments for kids

    These egg experiments are fantastic fun!

    Find out how to transform egg white into beautiful meringue!

    child making merginue to learn about kitchen science
    Making Meringue

    Make your own rock candy!

    Or, go all out and have a Science Bake OFF!!

    You can find lots more GROSS Science experiments in my new book too!

    Gross Science book for kids

    Last Updated on April 30, 2021 by Emma Vanstone

    « Bubble Science – fun with bubbles
    Preschool Science Experiment – Wet and Dry »

    Safety Notice

    Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

    These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

    Reader Interactions

    Comments

    1. julie

      March 05, 2012 at 5:05 pm

      Another great experiment. Thank you so much.

      Reply
      • ScienceSparks

        March 06, 2012 at 9:50 pm

        I’m so glad you like them!

        Reply
    2. HELEN

      March 06, 2012 at 7:32 pm

      ewwww, wouldnt have expected that with the lemon juice….the husband left an apple on the side in the kitchen when we went away for a week last August, considering the heat that our kitchen reaches (it’s also a conservatory) I feared the worst……and was surprised that it looked exactly the same as when we left!
      x

      Reply
      • ScienceSparks

        March 06, 2012 at 9:50 pm

        I know weird hey!

        Reply
    3. Chrissy @ The Outlaw Mom Blog

      March 07, 2012 at 6:27 am

      This reminds of the lyrics in the theme song for Sid the Science Kid 🙂 Cool idea. I’d have to make sure my son didn’t eat the experiment – mold and all!

      Reply
      • ScienceSparks

        March 08, 2012 at 10:57 pm

        sounds like my son. 🙂

        Reply
    4. Ali

      March 07, 2012 at 10:43 am

      What a great experiment. Must try it.

      Reply
    5. maggy, red ted art

      March 07, 2012 at 6:30 pm

      HA! I like Ali’s “Must try” comment above me.. though fascinating.. I am not sure I really want to try it… mouldy things.. yukky!

      Thanks for sharing on Kids Get Crafty!

      Maggy

      Reply
      • ScienceSparks

        March 08, 2012 at 10:57 pm

        ha ha, that made me laugh Maggy!

        Reply
    6. Cerys @ Rainy Day Mum

      March 10, 2012 at 11:00 pm

      I remember doing a similar science experiment with bread in different conditions when in year 7 and then teaching the same experiment a umh number of years later – but this with apples would add a new spin on it.

      Thank you for sharing with Tuesday Tots and look forward to seeing you again next week.

      Reply
    7. Ticia

      March 13, 2012 at 8:20 pm

      Ugh that lemon juice one is icky. I guess I’m still finding enough things like that by accident from forgetful kids that I”m not quite ready to try it 🙂

      Reply
    8. Larisa Garpstas

      September 21, 2018 at 12:18 pm

      I tried this and got opposite results. I set it up exactly like you said and showed in your pictures. My salt water apples were by far the WORST! And my lemon juice apples were the best. My science biology teacher friend explained that the acid in the lemon juice and vinegar prevents mold better. The salt pulled the sugary juice from the apple and bacteria (mold) formed on that.

      Reply
    9. skylee bailey

      November 30, 2019 at 7:13 pm

      This helped me so much with my science fair project thank you . You are a life saver.

      Reply

    Leave a Reply Cancel reply

    Your email address will not be published. Required fields are marked *

    Primary Sidebar

    • Email
    • Facebook
    • Instagram
    • Twitter
    • YouTube

    What are you looking for?

    JOIN US!

    Get new experiments straight into your inbox every week!!

    Thank you!

    You have successfully joined our subscriber list.

    .

    Footer

    ↑ back to top

    Science Sparks - FREE science experiments for kids

    Newsletter

    • Sign Up! for emails and updates

    Contact

    • Contact
    • Privacy Policy
    • Services
    • Media Kit
    • FAQ

    As an Amazon Associate I earn from qualifying purchases.

    Copyright © 2022 Science Sparks - Wild Sparks Enterprises Ltd