Experimentbeginnerdraft
Growing sugar crystals
Also searched as: making rock candy, crystal experiment, sugar crystals
In short: Over several days, sugar crystals grow on a string from a hot sugar solution.
Picture it
Like icicles growing drop by drop: a little more builds up each day.
Before · Afterday one
You need · a few days
- 250 g sugar
- 100 ml water
- a clean glass
- a wooden skewer or cotton string
Hot sugar syrup: only adults boil and pour.
How it’s done
Sequence · Step 1 of 4
Bring the water to the boil and dissolve the sugar in it completely.
All steps as a list
- Bring the water to the boil and dissolve the sugar in it completely.
- Let it cool a little and pour it into the glass.
- Dip in the skewer or string without touching the bottom.
- Leave it undisturbed for a few days.
What you see
Sparkling crystals grow on the skewer, a little bigger every day.
Why it happens
Hot water can dissolve far more sugar than cold water. As it cools, the sugar wants to turn solid again and builds up on the skewer. That is exactly what makes caramel grainy.
Related entries
Sources
- Harold McGee: On Food and Cooking (2004)