Dextrin is a material much used to make stars. It acts partly as a fuel, but mainly as a binder. |
Dextrin can be bought, but it is very easy to make.
Cornflour when heated to the right temperature changes to dextrin - it's that simple.
My method is to put a 1/2" layer of cornflour in a metal baking tray and place it in a hot oven (200 degrees Centigrade) for about 2 hours. Stir it around every 1/2 hour or so to ensure it's all cooked.
After 2 hours, it should have changed from white to light yellow. If it goes brown or black, the oven is too hot!
A little experimentation may be required until you have got a good idea of the temperature of your oven - they do vary.
In theory if you add a little of your product to some water with a crystal of iodine in it, it should not turn blue. This is a test for starch, and all the starch should have been converted to dextrin.
In practice I have never bothered with this and the dextrin has done it's job perfectly.