Answer:
Temperature and humidity
Step-by-step explanation:
Crystallization occurs in super saturated solution. These are the solutions that have solute to solvent ratio of 2:1 or more. Typical honey is 70% sugar and 20% water (the solute concentration is too high).
Two things cause honey to crystallize.
- Temperature
- Humidity level
If temperature is lowered the rate of crystallization increases. This is because at low temperature the molecules of solvent come closer and the space between them reduces. This causes the additional solute molecules to be pushed up to form crystals.
Secondly, humidity also plays a key role. If the humidity reduces, the water molecules evaporates from honey into air. This increases the relative concentration of the solute inside the honey, which causes the honey to crystallize.