Cornstarch
Cornstarch is ideal for thickening, but does not have a pleasant flavour. Too much corn starch in a liquid sauce will give a jelly-like consistency. In baking, corn starch often gives a more pleasant texture, but can give a very hard, dense consistency.
Rice flour
Rice flour is close to wheat flour in behaviour, taste, absorption, and thickening. However, it lacks any binding ability whatsoever, and works best when combined with other flours and starches in baked goods; delicate baked goods may fail if attempted with rice flour alone.
Sweet rice and white rice flour is finer than brown rice flour, although mills are now producing fine brown rice flours for the gluten-free market. Choose the finest grind possible for gluten-free baking; coarser grinds are slightly gritty.
Brown rice flour is a whole grain flour containing higher protein than the white rice flours, and imparts a pleasant heft to baked goods. Sweet white rice flour from a Chinese or Asian grocery is as fine and powdery as cornstarch, and behaves similarly in baked goods. Sweet rice flour can be used as a thickener in gravies. Brown rice flour also makes a good roux for cheese sauces, gumbos, or brown sauces.
Potato starch
Potato starch is a light starch that will rise with egg as the leavening agent. Allows lighter baked goods. Use is limited by the short shelf life of products made using this starch.
Potato flour
Potato flour is a pleasant thickener for gravies and can also be used in baked goods. Some bread recipes also use mashed potato flakes!
Xanthan Gum
A strong binding agent that is used to replace the “stretchy” quality inherent in gluten, xanthan gum is often added to gluten-free flour blends to promote an improved texture. Use sparingly in bread, cake and cookie recipes. Xanthan gum is the fermentation product of the bacteria Xanthomonas campestris.
Other binders
Xanthan gum is the most popular binding agent, but others can be used too. These include soya lethicin, guar gum, carageenan, carob (locust bean) gum and even gelatin. These agents are often used in combination with each other.
Tapioca starch
Tapioca starch is a thickening agent often used in Chinese foods and gum candies. This starch is derived from cassava (aka manioc) roots; it is the same tapioca as in tapioca pearls, or tapioca pudding. Best used in combination with other gluten-free flours.
Chickpea Flour
Flour made from chickpeas, a popular alternative to gluten flours. This flour is commonly used in Indian cooking and can often be found in Indian or Asian grocery stores, sometimes labelled “besan”. It has an unpleasant taste when raw but has a good approximation of wheat flour’s texture when cooked. Unfortunately, some may find that it promotes flatulence.
Sorghum Flour
Sorghum flour (also known as sweet sorghum or jowar) makes an excellent wheat flour substitute in quick-leavened baked goods such as muffins or banana bread. It is ground from the small, millet-like grains of the sorghum plant (used to make sorghum syrup). Sweet white sorghum flour is a pale pinkish-brown in color and has a pleasant, faintly sweet and grassy taste. It is best combined with a gluten-free starch such as cornstarch or tapioca and creates a fine crumb, good texture.
Skim Milk Powder
Gluten-free bread recipes often contain skim milk powder. It adds protein and also has beneficial effects on the end product. The casein in milk makes it a good emulsifier, and it makes for a finer crumb and better consistency. People who are allergic to dairy can try substituting soy milk powder, but the results will not be as good.
Soya flour
Soya flour is also often added to gluten-free bread recipes to add protein.