Warning to people making fondant for candy boards. Follow the recipe! Or experiment in SMALL batches. I was making fondant from a recipe link posted here (first time). I put a little lemon juice in the mix and I tested it's ability to harden and it was working just fine. Then I decided to add some soy flour for some protein boost to the mix. This SIGNIFICANTLY lowered the crystallization temperature. I spent hours adding more sugar, stirring, heating, testing... It was a late night. I finally got it to work, and now have two candy boards each weighing close to 50 lbs. (Was planning on doing ONE that night.) Also found out that just because fondant will harden in a small glob, does not mean that it will harden in a large pour, at least not before it seeps all over the place. Even with pouring in just a little to seal the bottom of the board first. The rest of the pour was still finding a way out. Even with the mix finally hardening, I found it best to pour in small batches - like 3/4" thick. I also discovered that it is finally right when whatever splashes up on the inside wall of the pot hardens quickly.
Good luck everybody! If I finally figure out the real amounts, and if it works well for the bees, I will eventually post the recipe.
JC