Xanthan Gum or Guar Gum

I thought this was a great tidbit from livingwithout.com

General Guidelines for Using Xanthan or Guar Gum

Gum (xanthan or guar) is the key to successful gluten-free baking. It provides the binding needed to give the baked product proper elasticity, keeping it from crumbling.

• Add 1/2 teaspoon xanthan or guar gum per cup of flour blend to make cakes, cookies, bars, muffins and other quick breads.
• Add 1 teaspoon per cup of flour blend to make yeast bread, pizza dough or other baked items that call for yeast.

Note:

If you purchase a commercial flour blend, read the ingredient list carefully. Some blends contain salt and xanthan or guar gum. If so, there is no need to add more.