Growing sugar crystals is a great experiment for kids as you can observe the results over a few days and watch how the crystals form on your lollysticks. You could even try different colours and flavours in your sugar lollies. How about peppermint flavour for Christmas?
How to grow sugar crystals
What you need:
3 cups of caster sugar
1 cup of water
A lolly stick
A jar or bowl
Some sparkles and/or food colouring( optional )
Place the sugar and water into a pan and heat whilst stirring until the sugar has dissolved ( ask a grown up to help with this part ). Leave to cool for a little while. Add a few drops of food colouring or edible sparkles, but this is optional.
Pour the solution into a glass jar and suspend the lolly stick, we used a fork to hold it in place. Don’t let it touch the bottom or the sides.
You should see crystals start to form after a few days.
The Science Bit
A crystal is a solid material with a naturally geometrically regular form. Some take millions of years to form, such as diamonds. The crystals we made above take just a few days.
Most minerals dissolved in water will form crystals given enough time and space. The shape of the crystal formed depends on the mineral’s molecule shape.
In the case of our sugar crystals there are two processes at work.
Evaporation – the water evaporates slowly meaning the solution becomes more saturated, so the sugar molecules come out of solution and collect on the string/wire or stick.
Precipitation – the solution we made was very concentrated which means there was too much solute to remain dissolved in the water, therefore it starts to precipitate.
If your crystals don’t grow very well, try seeding the lollystick first by putting some sugar on the end, this will give the crystals something to stick to.