Banana Ripening Biology Experiment

Using bananas, test how different temperatures and environmental conditions affect the ripening speed of bananas.

Why use bananas?

  • cheap
  • can be bought unripe and will ripen
  • visible change in ripening


Independent variable is the environment, since it is not dependent on anything but the experiment (we’re not going to conduct this outside).

Dependent variable is the ripening speed of the bananas, because this is changing based on the environment.

Background Information

Bananas, as most people know, are yellow when ripe and have a soft yellow flesh that is sweet. They can ripen independently from their plant, as can be seen when you buy a green one and leave it on your counter. Like other fruits, there are factors which influence the speed at which they ripen. A major factor influencing the ripening speed of fruit is the presence of ethylene.

Ethylene is a hormone produced by most fruits; it is a colorless gas with the chemical formula H2C=CH2 (the carbons are double-bonded). Ethylene is lighter than air, which makes it diffuse rather rapidly. When a fruit is exposed to ethylene, it ripens at speeds faster than it would without. Oxygen is necessary for this reaction as well. Every fruit reacts differently to ethylene; bananas are heavily affected by it, while most berries are not.

Of course, there are obviously other factors which influence the speed at which all fruit ripen, e.g. disease, temperature, light exposure…


If you place a banana in a warm environment with large amounts of ethylene gas, then the banana will ripen faster.

Material List

  • 7 unripe (green) bananas – NOT baby bananas or plantains
  • a refrigerator or other cool (1 to 6°C) place
  • a freezer (-10 to -2°C)
  • two plastic bags (not airtight)
  • two ripe or half-ripe apples
  • a large closeable (not airtight) cardboard box


  1. Make sure all bananas are about equally unripe; if there is a significant difference between any two, then get new bananas.
  2. Take one banana. Look it at, note the color, peel it, and take a bite; record the taste (the sweetness) in your data table. Feel the banana; is it hard and firm or soft and mushy?
  3. Place one banana under normal conditions. This means somewhere around room temperature, good light exposure, on the kitchen counter or some similar place. This will act as the control.
  4. Place one banana in the refrigerator, away from any clutter (e.g. eggs, parsley, oranges…)
  5. Place one banana in the freezer, again away from clutter
  6. Place one banana in each plastic bag. Close one off so that not much oxygen gets in, but make sure to leave a connection with the outside world. In the other bag, place the two apples and close it off like you did with th first.
  7. Place one banana into the box and close the box, to make that banana in relative darkness compared to the control
  8. Wait two days, then remove each banana from its environment, making a careful note of where each one came from
  9. Perform Step 2 with each banana; observe it, taste it and feel it, and record it in your data table.

    Note: Do not taste a banana with brown flesh – it is rotten and overripe.

  10. Dispose of the bananas after the experiment.

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25 Responses to “Banana Ripening Biology Experiment”
  1. sashatalia Says...

    On December 22, 2008 at 4:02 am

    i am doing a project on this

  2. sha-sha Says...

    On December 22, 2008 at 1:08 pm


  3. jakaka Says...

    On January 13, 2009 at 2:18 pm

    i am doing a project on this but i need to find out the results of this experiment for my science fair paper

  4. Bella Says...

    On January 19, 2009 at 3:42 pm

    I like bananas and Robert pattison

  5. guy Says...

    On January 22, 2009 at 8:52 am

    i am doing this project too

  6. dude Says...

    On March 8, 2009 at 3:13 am

    iam doing the exact same project but can u tell me more about the experiment

  7. joker Says...

    On March 12, 2009 at 11:39 am

    umm i kneed results

  8. Al Says...

    On March 16, 2009 at 7:24 pm

  9. jessy Says...

    On April 1, 2009 at 3:37 pm

    i need help with this project because i’m doing it for my stem fair project

  10. gail Says...

    On August 1, 2009 at 6:04 am

    were using this project for our scientific method, what plants can help the bananas to ripen faster, please reply

  11. gizmo N. Says...

    On August 3, 2009 at 3:16 am


  12. makaya Says...

    On December 8, 2009 at 4:38 pm

    you need to have a purpose here!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! duh.

  13. Banana LADY Says...

    On January 24, 2010 at 1:28 pm

    im doing this but with just bananas and instead of in the freezer and fridge im doing it in normal counter conditions vs. in plastic ziploc so far the results have been , the plastic bag bananas stayed greener than the normal ones.

  14. Ernest Gilbert Says...

    On February 2, 2010 at 4:04 pm

    My name is Ernest. I am doing a simialer prodject for my fith grade sciense prodject. I am wondering if you can give me any tips on what to do. Please reply at

  15. gab Says...

    On March 7, 2010 at 10:28 pm

    i’m doing a similar experiment but one exposed to air, one wrapped in foil, one in plastic wrap and one in ziplock. can u give me feedback on results of ur experiments?

  16. jennifer Says...

    On March 20, 2010 at 12:50 pm

    i loooooooooooooooooooove bananas

  17. babyblue2498 Says...

    On April 19, 2010 at 10:59 pm

    i do not get this at all

  18. babyblue2498 Says...

    On April 19, 2010 at 11:00 pm

    i looooooooooooooooooooooooooooooooooooooooooooooooooooooooove banananas they are ver y soft mushy i looooooooooove baananas go bananans

  19. jeov Says...

    On September 25, 2010 at 10:37 pm

    i am doing an investigatory project on bananas. thank youuu…. for sharing this… it gives me more ideas.

  20. weiuofwiei kjwkjdfeqwlkj Says...

    On December 8, 2010 at 7:28 pm

    what about strawberries

  21. milly Says...

    On March 6, 2011 at 10:12 pm

    i have till monday the7th to finish so im freckin out

  22. Gabby Says...

    On April 7, 2011 at 6:38 pm

    hi i need help??????????????!!!!!!!!

  23. NONEYA Says...

    On September 12, 2011 at 4:51 pm


  24. bob Says...

    On November 10, 2011 at 10:10 pm

    fuck you bitch

  25. Gizmo Says...

    On February 1, 2013 at 11:14 pm


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