Making Dextrin

Dextrin is pretty easy to make and is a useful compound. It is used as a binder for many star compositions, for lift powder, and for blackmatch among other things. And not only is the procedure for making it easy, but all you need is corn starch (or corn flour if you live in the UK).
Here's a picture of the corn starch that my mother was kind enough to supply:



Now the procedure is quite simple - it's just hydrolysis of the starch. And how is this gone about? Just heat it. I spread the starch out fairly thinly on a pan and stuck it into a toaster. I set it to around 350-400 Fahrenheit and let it sit for about an hour (for smaller amounts) to around 2 hours (for larger amounts). The exact time I leave it for is usually something I determine by eye after seeing how it progresses. From time to time I'll move the starch/dextrin around to make sure it all gets evenly heated and not burned. The starch turns from white to a nice golden brown dextrin. And that's it, the dextrin is ready to use.
Here's a picture of some that I made:



You can test to see if there was a full conversion by 1. testing if it dissolves in water (it should) and 2. testing if the solution does not turn purple when iodine is added (it shouldn't).

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