Flutterby™! : Model rocket fuel

MarkV shared this video of a fairly large amateur rocket noting that the propellant used was "rocket candy", a mixture of sugar and potassium nitrate (which I've done before with kids for smoke bombs), although they apparently use corn syrup as a binder (rather than fully melting the sugar, they just cook out the liquid), and iron oxide (rust) as a catalyst.

Discussion ensued, and Mark then pointed out that sorbitol makes a less brittle fuel and has a much lower melting temperature, giving a larger safety margin and making it a good rocket fuel.