Growing crystals at home

Have you ever tried growing crystals at home? If you visit the shops with your parents, I am sure you have seen crystal growing kits before, but there are also plenty of tutorials online so I decided to do at home because I knew I would learn more.

You can make many different type of crystals with every day items, but I choose sugar because apart from looking nice they are edible.

Every crystal starts with the same process, by making a saturated solution. A solution is when we dissolve something called the "solute" into a liquid called the "solvent". In my case, sugar is the solute and water is the solvent. At the beginning if we put some sugar in the water and stir it will disappear, but if we keep adding sugar, eventually it will not disappear. This point is what we call a saturated solution. 

Normally, you would expect that the amount of solute you put in is less than the solvent. That is true for most things, but not for sugar. Surprisingly, you can put up to a 2-to-1 ratio of sugar to water. For example you can put 200 grams of sugar into 100 grams of water. 100 grams of water is 100ml. This at room temperature. If the water is boiling you can 4.5 times!!

That's what I did and I also added food coloring so that crystals would look cooler. I made two batches: a blue one and a red one. I put it in the pot and heated it up  to make boil. It became a think syrup as you can see in the photo.

Another thing I learnt is that the boiling point of a water increases when it has a solute. Notice how in the previous photo, the boiling point is 101.5 degrees Celsius instead of 100. Typically, this also affects the freezing point making it lower than 0 degrees, that's why they put salt in roads where ice builds up, although I don't see much of that in Australia.

Growing Big crystals need a seed, which is a small crystall. This is needed to prevent small crystals growing every where. I wanted my crystals on a stick so so I coated a skewer in the syrup and rolled it into sugar granules and let it cool down. That was my seed

Then I put the syrup in a container and place the skewer in the middle of the container without touching the bottom. I used the peg trick that you can see in the photo. Otherwise the crystal will stick to the bottom. Finally, we cover it and let it grow.

Mine grew for a month but every week I was cleaning out the crystals that were appearing on the sides and bottom. This is important because this small crystals compete with your crystal for resources. They reminded me of a geode.

This is a video of when I harvested them

There was quite a lot of syrup left, so after harvesting them I decided to add yellow colouring to both solutions to produce an orange and a green crystal. They got smaller because there was little solution left. This is the end result with all 4 crystals.

I tried them but unsurprisingly, they tasted too sugary ... but they still looked nice.

In the future, I might try to grow new ones out of something else.

See you next time !