Xanthan gum is a powder that is frequently used in gluten-free baking. It has the ability to add volume to baked goods without using flour, which people with gluten allergies are allergic to. It can also be used to thicken gravies or salad dressings. Although xanthan gum can be expensive, a little bit goes a long way. Most recipes only call for one to two tablespoons of the product. Xanthan gum can be found in larger grocery stores that carry gluten-free products as well as co-ops and natural foods stores. It can also be ordered online.

Look in the gluten-free section of your local grocery store. Larger grocery store chains often have a special section of the store where gluten-free products are available. Xanthan gum can usually found in this section, although it is occasionally shelved in the baking aisle. If your grocery store does not carry xanthan gum, ask the general store manager to order it.

Visit a food co-op or a natural foods store. Co-ops and natural foods stores tend to offer more products for people who are looking for gluten free alternatives. If you can't find xanthan gum, consider purchasing guar gum. Like xanthan gum, guar gum is a gluten-free powder that is used as a thickener and volume enhancer in baking.

Order online. Amazon offers a large variety of xanthan gum powder. You can also find it at Vitacost, House of Nutrition and iHerb.com. The product is available in four-ounce, six-ounce and eight-ounce packages.