Xanthan Gum 101

• Xanthan gum occurs when the bacteria Xanthomonas campestris ferment on sugar. It is corn-based and synthesized in laboratories. Food manufacturers use it to make salad dressing creamier or to improve the consistency of toothpaste. Xanthan gum mimics wheat flour protein, or gluten, giving elasticity to dough. It also acts like an emulsifier, suspending oil in water evenly; providing uniform texture in baked goods; and reinforcing crumb structure, volume and sponginess in breads and cakes.

Xanthan Gum in Batters

• Xanthan gum's viscosity increases the more you mix it. After adding it to a batter, stir the batter just long enough to fully incorporate the wet and dry ingredients. When preparing batters with added xanthan gum, especially drier batters like cookie dough, let the batter rest refrigerated before using it so the xanthan gum has time to hydrate completely. This also allows the batter to congeal, which helps to stabilize expansion during cooking.

Xanthan Gum-to-Flour Ratios

• With different types of low-protein or gluten-free flour recipes, varying amounts of xanthan gum tend to yield the best results in terms of texture and thickness. For muffins and quick breads, 3/4 teaspoon of xanthan gum per cup of flour is sufficient; as is 1/2 teaspoon per cup of flour for cakes. A 1/2 teaspoon or less seems to be enough for cookie and bar batters, while 1/4 teaspoon xanthan gum, or none at all, works well in pancake and crepe batters.

Rescuing a Thick Batter

• Much like gluten, xanthan gum continues to absorb moisture the longer it sits. Depending on many factors, such as humidity and how much liquid your batter contains, you can end up with batter that is too thick to stir or pour -- or even cook with. To remedy, beat some room-temperature milk into the batter 1 tablespoon at a time until you reach the desired consistency. This technique also works for thinning batter to which you've added a little too much xanthan gum.