The two principal sugars in raw honey are fructose and glucose . The content of fructose and glucose in honey varies from one type of honey to the other. Generally, the fructose ranges from 30- 44% and glucose from 25- 40%. The balance of these two major sugars causes the honey crystallization, and the relative percentage of each determines whether it crystallizes rapidly or slowly. What crystallizes is the glucose, due to its lower solubility. Fructose is more soluble in water than glucose and will remain fluid.
When glucose crystallizes, it separates from water and takes the formof tiny crystals. As the crystallization progresses and more glucose crystallizes, those crystals spread throughout the honey. The solution changes to a stable saturated form, and ultimately the honey becomes thick or crystallized.