Science Experiments you can do in a Jar

Here at Science Sparks, we try to make science as easy and accessible as possible. When I ask people why they don’t do more science at home with children, one of the answers is usually that science experiments are messy. While this can most definitely be true, there are also lots of non-messy science investigations and experiments around. One of the easiest ways to reduce mess is to try a science experiment in a jar! The jar or glass keeps most of the mess in one place, and the activity can generally be poured away afterwards.

I’ve pulled together a list of our favourite science experiments in a jar to make science at home even more accessible! Most of these also work with a tall glass if you don’t have a jar.

Make fireworks in a jar, grow a bean in a jar, practice estimating, make a DIY barometer and lots more. Which will you try first?

Science Experiments in a Jar

1. Fireworks in a jar

This lovely, colourful science experiment is super easy to set up and carry out but looks fantastic! Watch as swirls of food colouring burst through the oil into the water.

a tall glass filled with water and a layer of cooking oil. Swirls of food colouring are shooting through the oil into the water.

2. Lift an ice cube with a string

Use salt to lift an ice cube out of a jar or glass with a piece of string! Salt lowers the freezing point of water, so the ice melts a little and then refreezes around the string.

lift ice with string and salt science activity

3. Dancing raisins

Use baking soda to make raisins dance around a glass of water!

Raising Raisins - dancing raisins in a glass

4. Make butter from cream

You’ll need some strong arm muscles for this one! Shake a jar of cream for about five minutes, and it will turn into butter! This is a good activity for learning about emulsions and colloids.

cream in a jar that has separated into butter and a milky liquid

5. Floating eggs

Discover how adding salt to water affects its density with this simple science demonstration using an egg!

cartoon image showing an egg floating in salt water and sinking in fresh water

6. Tooth decay experiment

Soak eggs in vinegar and water for two days to see what happens! This is a great way to demonstrate how acidic food affects tooth enamel.

Two eggs. One is soaking a jar of vinegar and one a jar of water for a tooth decay science experiment

7. Pumping heart model

This pumping heart model is a great demonstration of one chamber of the heart and valve. It’s also something you can keep and use over and over again!

pumping heart model made with a jar, straw and balloon

8. Tornado in a jar

Learn all about tornados ( also known as twisters, cyclones or funnels ) with this simple tornado in a jar demonstration.

Image of a tornado in a jar with a background of a real tornado

9. Make a barometer

Learn about air pressure and how it impacts weather with this simple homemade barometer made from a small jar, balloon and a wooden stick.

homemade barometer made with a glass jar, balloon, skewer and tape

10. Easy density jar

This density jar is a brilliant way to demonstrate the concept of density to children. The most dense liquids are at the bottom and the least dense at the top. As an extension challenge, children can try to find different small objects to float on each layer.

11. Salt lava lamp

This simple salt lava lamp is a fun twist on the more traditional homemade lava lamp that uses a fizzy tablet. Although the salt lava lamp doesn’t look quite as good and isn’t as reusable, it is still a lovely science activity for learning about density.

salt lava lamp made with water, oil and salt

12. Oil and water lava lamp

Homemade lava lamps are one of our favourite science experiments. They are super simple to make, can be used over and over again, and allow you to be as creative as you like. Just drop an effervescent tablet in and watch the fizz!

13. Bean in a jar

Grow a bean in a jar with just a little water. This is a great science activity for learning about germination and the environmental factors needed to make it happen.

14. Rain cloud in a jar

Find out why and how rain falls with this fun and visually appealing rain cloud in a jar.

15. Estimating jars

These aren’t a science experiment as such, but being able to estimate is a handy scientific skill. Fill a jar with small seasonal items and ask kids to estimate how many of each are in the jar!