Making gelatin for casting

I am an absolute neophyte when it comes to casting.
A question for anyone who has used the gelatin/glycerine approach to casting:

The recipe I have calls for gelatin, glycerin, water, denatured alcohol, and glucose.
My question is twofold- First, what role does the glucose play in the formula? As a hardener/curing agent? And second- I have absolutely no idea where one finds this, so is it absolutely essential to the recipe?

Thanks in advance!

A follow-up to my initial question- has anyone ever used parafin to cast a piece? Is it easier/cheaper than using a gelatin/glycerin mix?

wax and gelatin for molding are not the best ways to go neither will last beyond one cast. wax is used for making lost wax casting which involves covering the wax in a type of plaster and then burning the wax out of the plaster and pouring in molten metal. gelatin is an old school technique for making facial prosthetics for movies. you may have better results using silicon caulking for your small mold making. larger molds can be done with a plaster called hydrostone, have a look around the site for tutorials. that may answer a lot of your questions. good luck with your project.