Gluten-free flours have different properties when baking and cooking to ordinary (wheat) flour due to the lack of gluten. Gluten-free flour requires different cooking techniques. Understanding a bit about how gluten contributes to the texture of food can get you a long way towards understanding gluten-free cooking.
 
For example, bread is made as a batter consistency, and biscuits and pastry are less crumbly if kneaded and left in the refrigerator for half an hour before rolling and cutting.
 
 

Gluten chemistry

Wheat, barley, rye and oat grains contain amongst other things two proteins: Glutelin and Prolamin (named differently for each grain: wheat – gliadin; barley – hordein; rye – secalin and oats – avenin).
 
During dough-making (cakes, bread, pastry etc.), gluten is formed when the glutenin molecules cross-link (share chemical bonds) to form a microscopic network and associate (held by electrostatic attraction) with the prolamin molecules.
 
If yeast is added to the dough carbon dioxide bubbles are formed which are trapped by the gluten network and cause the dough to rise. Baking coagulates (makes it insoluble) the gluten, which, along with the changing structure of the starch during baking, stabilizes the shape of the final product.
 
Kneading promotes the formation of cross-links so the more products are kneaded the chewier they are. While bread is kneaded, Chewier products like pizza and bagels require more kneading. Cakes just need to be mixed. The flours used to make bread items are higher in gluten while cake flours are low in gluten.
 
The amount of gluten is also proportional to the amount of water used in the recipe. Adding shortening (butter, lard or margarine) inhibits the formation of cross-links so using fat along with less water and minimal working.
 
Over time baked goods become stale. This is not primarily due to moisture being lost from the baked products, but more a change in the chemical relationship between the water and the starch into a harder structure.
 

Gluten-Free Chemistry

The explanation of gluten chemistry gives you an idea why it’s easier to get good texture for a gluten-free cake or pastry than it is for a pizza base or loaf of bread. Pay close attention to the ingredients, quantities and methods described in the recipes and be prepared to experiment a bit until you find a recipe that you like.
 
Flours used in gluten-free cooking will typically be made up of gluten-free wheat starch or a mixture of other flours (rice, tapioca, potato, buckwheat, gram (chickpea) – all from certified gluten-free sources) and thickening agents to act as a replacement for the gluten.
 
Common gluten replacements are:

• Xantham gum
• Guar gum

 
Xantham gum is a biopolymer (a class of polymer produced by living organisms). Polymers form long chains of chemical bonds which means they are an effective replacement to gluten. Xanthan gum produces a large increase in the viscosity of a liquid by adding a very small quantity of gum from 0.5% to 1%.
 
Guar gum is economical because it has almost 8 times the water-thickening potency of cornstarch - only a very small quantity is needed for producing sufficient viscosity. Thus it can be used in various multi-phase formulations: as an emulsifier because it helps to prevent oil droplets from coalescing, and/or as a stabilizer because it helps to prevent solid particles from settling.