Easy Science Experiments For Kids: A cloud in the bottle

Here follow my instructions for the cloud in the bottle experiment. This one me and my kids tried several times before we understood that we had succeeded. First, we thought that we were too fast to drop down the matches, and did not get enough smoke into the bottle. But that was not the case, the magic happened when we added pressure to the bottle!

Parental supervision is a must since the experiment involves matches and fire!

Remember to start the experiment with a hypothesis, what do you think will happen?

Instructions for parents: Read this first.

Material included:

  • A plastic bottle
  • Matches
  • Water


  1. Fill the bottom of the bottle with some room-tempered water.
  2. Screw on the cork and shake well.
  3. Loosen the cork, but open it as little as possible so that the humid air stays in the bottle.
  4. Take three matches and light them at the same time, let them burn for a little while, and then drop them into the bottle. NOTE! Don’t be too fast here! Don’t drop the matches down immediately, keep them at the bottle mouth so that as much smoke as possible is collected in the bottle.
  5. Quickly screw on the cork again.
  6. Study the smoke in the bottle, note what happens.
  7. Try again to press the bottle firmly (hold it for a while). What happens?
  8. Then note what happens when you release the pressure on the bottle.
  9. Try to press and release the bottle freely? When does the cloud come forward and when does it disappear?


In order for the cloud to be formed, some things are required. Firstly, there must be water in the air (water vapor), then the air must be cooled and finally the steam must have the help of small particles to “condense” – become water droplets.

When you shake the bottle, the air humidity increases in the bottle, and there will be more water vapor in the air. By pouring some smoke into the bottle, the necessary particles that help water vapor is added. Then we need to cool the air – this is done when we press the compressed bottle -> lower pressure = lower temperature.

To see others do the experiment look at this video:

Click the link to get to my Kids Christmas Calendar.

Do you have any questions or comments about the experiment? Just leave a comment below!



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