I haven't used Expandex yet, but someone in my local celiac support group tried it. She said it worked more like flour than any other GF flour substitute that she had ever tried.

Dumb question: I thought guar gum, like xanthan gum, was grown on corn. I have a corn-sensitive kid, so I'd been avoiding both. If guar gum is ok, that opens up some interesting baking possibilities for us.

-Valerie