> Honey is about 70% fructose + glucose.
> It's about 16-19% water.
> So I'm not sure why it would caramelise at significantly lower temperatures than its constituent parts would suggest.
Wikipedia states:
> The temperature at which caramelization begins varies, depending on the composition, but is typically between 70 and 110 °C (158 and 230 °F). Honey also contains acids, which act as catalysts for caramelization. The specific types of acids and their amounts play a primary role in determining the exact temperature.
The citation is "Zdzisław E. Sikorski Chemical and functional properties of food components CRC Press 2007 p. 121 ISBN 0-8493-9675-1". It's not publicly available, so I can't cite it, but if you're really interested you should try to find and read it.