Lois, what did you use for the potato part of the "2 cups GF Flour Mix (I used the 6/2/1 rice (1/2 brown,1/2 white)/potato/tapioca)"? Did you use the instant mashed potato flakes? If you did, that's probably why the bread was so heavy. When you see something like 6/2/1 (rice/potato/tapioca) it means potato starch. If you subbed another starch in, then...I don't know. Sorry.

I know the first GF bread I tried to make, I didn't know the difference between potato starch and potato flour, so I used potato flour. That's the loaf that baked for 2 hours and still seemed moist/doughy in the middle. It had good flavor, but it was VERY heavy and VERY dense. Most of it got tossed because I didn't think it was done. LOL

As for the recipezaar bread, my mom used buckwheat in place of the sorghum. She said it turned out really good. If you don't have potato starch, I would use arrowroot or cornstarch. Good luck. It really is a good recipe.

Edited to add: I'm sorry, I saw your post about using arrowroot to sub for potato starch in another thread. I thought I'd seen something about that, but couldn't remember where. Then I don't know why it turned out so heavy.