Xanthan gum

Xanthan gum is a polysaccharide gum produced by growing the bacterium Xanthomonas campestris in a pure-culture fermentation, then purifying it by recovery with isopropyl alcohol, as described in the federal food additive regulations. It is sold as a fine, creamy-white powder.

A very small amount thickens liquids and holds ingredients evenly in suspension. In baking its best-known job is in gluten-free breads, cakes and cookies, where it gives batter and dough some of the stretch and structure that gluten would normally provide, and it helps keep the crumb from turning dry and crumbly. It is also used in fruit fillings, glazes and sauces so they stay smooth.

It clumps easily, so it is whisked into the dry ingredients first or blended into the liquid.