Xanthan gum is a flavorless thickener used in many foods and other commercial products. It is a microbial polysaccharide produced by natural fermentation by the bacterium Xanthomonas campestris.
In addition to thickening, xanthan gum helps keep solid particles in suspension, which is useful in products like bottled salad dressing. It provides an even texture and uniformity in a food and can improve mouthfeel. Xanthan gum can be bought for home use and is a great way to thicken and stabilize soymilk-based rice milk-based sauces, soups, and nondairy ice creams. It's often used in gluten-free baking as a replacement for the sticky effect of gluten.
How Xanthan Gum Is Made
Allene Rosalind Jeanes, a distinguished researcher for the U.S. Department of Agriculture, discovered xanthan gum and it was developed for commercial use. The FDA deemed it a safe food additive in 1968.
Xanthan gum is produced by natural fermentation of corn, soy, wheat, or cabbage. The bacteria digest the sugars in these vegetables and produce a complex sugar polymer. Alcohol is added to make it drop out of solution. The xanthan gum is then dried and converted into a powder that can be used in food and other products.
How to Use Xanthan Gum in Cooking
Xanthan gum functions similarly to gelatin in recipes with regards to stabilizing suspensions, but it is completely vegan, while gelatin comes from animal sources. It's also great for cooking and baking for persons with food allergies and restrictions, especially for those who are omitting dairy, eggs, and soy from their diet.
No heating or cooling is needed for xanthan gum to form a gel—it does so as soon as it is in contact with a liquid. Acid and heat don't affect it, so it can be used in a wide variety of sauces and juices.
To use xanthan gum in recipes, use about 1/8 teaspoon per cup of liquid and combine these in a blender, not by hand. It will "gum" almost instantly and form clumps if not constantly in motion while it is being incorporated into the liquid.
For sauces, blending the xanthan gum first with a bit of oil before adding the soy milk or rice milk produces the best taste and texture, as this gives the sauce richness and depth that would normally be achieved by cream, butter or eggs. The more xanthan gum is used in a liquid the thicker it will become.
Is Xanthan Gum Safe?
In small quantities, xanthan gum is perfectly safe to consume. If you ingest more than 15 grams you may experience some intestinal discomfort similar to eating too much fruit. However, most people do not consume anywhere close to this amount of xanthan gum in a day.
Xanthan gum is made with things like corn or soy which can cause an allergic reaction in some. Because of the extraction process, there should be only trace amounts of residual proteins from the sources used in fermentation. These may still be a concern to those who are sensitive, but it is likely that the xanthan gum would test as being free of these allergens. While it's very rare for people to have an allergic reaction to xanthan gum if you are exceedingly sensitive to the base ingredients you might want to skip it. An alternative thickener is guar gum or locust bean gum.
If you happen to inhale xanthan gum powder (not recommended) you may experience some respiratory flu-type symptoms.
Other Uses for Xanthan Gum
Xanthan gum has medical uses for thickening liquids for people who have had strokes or other conditions that make it difficult to swallow thin liquids without choking. It is used in saliva substitutes for people with dry mouth conditions.
Many cosmetic companies also include it as an ingredient in lotions and liquid makeups. It has skin moisturizing effects which make it great for products used on the face. The oil drilling industry makes use of this common baking ingredient as a mud thickening agent.