What is xanthan gum and what is it good for? After consulting with some chefs, Molly Young buys a bag to experiment with in her own laboratory kitchen ...


Xanthan gum is that strange species of food additive, the high-low hybrid. On the one hand, it has a chemical formula that resembles a tangled ball of thread. On the other, it is available at supermarkets in handy 8oz bags, priced at a reasonable $12 (you only need a teaspoon per recipe). Wylie Dufresne uses xanthan gum at his restaurant in preparations like cilantro oil and faux foie gras; Ferran Adria uses it in ham consomme; Elizabeth Falkner mixes it into her homemade marshmallows and David Kinch adds it to vegetable purees. It is also present in Hellman's Light Mayonnaise and Kraft Caesar Salad dressing. Not often does one find an ingredient deployed in such disparate preparations.

There's also the fake-sounding superhero name––xanthan gum!––like something out of a Marvel comic book. Appropriately enough, xanthan gum has its origins in a laboratory. Discovered by Allene Rosalind Jeanes, a chemist, and her research team at the United States Department of Agriculture, it was tested on animals and approved for use in foods in 1968. Food scientists began using it to improve the texture of ice creams, salad dressings and pet food. Xanthan gum's viscosity-heightening powers also made it an excellent additive to fake blood.

But what is it, exactly? In its kitchen-ready form, a pale yellow powder. Chemically, something quite complicated.

I asked Dr James Hageman, an associate vice chancellor for research at the University of Colorado Denver, to explain the magic of xanthan gum. "Jeanes and her team found a bacterial plant pathogen that caused black rot in certain kinds of plants," he told me. "The organism, Xanthomonas campestris, produced a gooey stuff which they called xanthan gum." The word "pathogen", I pointed out, might cause alarm bells to ring for consumers. "People may balk at the fact that its made from a pathogen, but it's not a pathogen for us," Hageman clarified. He went on to say that because xanthan gum is heat stable, it can be sterilised to remove any live bacteria. "It's apparently easy to work with if you're in the food business."

Elizabeth Falkner, the executive chef and owner of Citizen Cake and Orson in San Francisco, likes xanthan gum because of its texture and emulsifying power.  "Xanthan works great in something like a marshmallow. It creates a light, fluffy texture," she says, which is quite unlike that of marshmallows made with gelatin. She also uses it in sauces as a thickener. "Eggs, cornstarch and gelatin are still more commonly used thickeners and emulsifiers than xanthan, but there are many starches and hydrocolloids which all have huge possibilities."

The potential uses of xanthan gum in the home kitchen differ from those in industrial food plants or high-end restaurants. Companies such as Bob's Red Mill market the substance mainly as a thickener for gluten-free baked goods, though it can also be used as an stabiliser in sauces and simple vinaigrettes. Out of a mix of curiosity and perversity––the mood from which most food experiments spring––I bought a package to conduct some free-form home trials. If Dufresne can make cilantro oil, surely I can make a silky pudding with xanthan gum, no?

The package I took home included a recipe for Gluten Free Zucchini Bread on its label. This did not exactly excite my taste sensors, so I decided to Google a recipe for gluten-free chocolate-chip cookies instead. Xanthan, I read, would be used to generate the stickiness that gluten might otherwise provide in the cookies. I have no problems with gluten, but in the interest of food science, I followed the recipe to the letter. Results were disappointing—the cookies looked pale, were oddly thick and tasted slightly off. If nothing else, the test served as a reminder that the Tollhouse recipe always prevails.

The next try was an impromptu one: I added a dose of xanthan gum to my morning oatmeal. This was a bad idea from its inception––while oatmeal can be many things, it should never be viscous. A teaspoon of xanthan turned my cereal into elastic mud. There was no change in taste, but the oatmeal vibrated when I set it down upon the table. Soon after it went vibrating down the drain.

Finally, pudding. Although the stabilising properties of xanthan theoretically make it ideal for pudding, I couldn't find a single appealing recipe online that incorporated the powder. Xanthan pudding recipes fit into two categories: the protein-packing bodybuilding variety or the appetite-suppressing, Splenda-using one. Neither would do. Instead, I found a recipe for old-fashioned vanilla pudding and simply whisked a tablespoon of xanthan gum in with the sugar, salt and eggs. After mixing, heating, pouring and stirring, I removed the pudding from heat, strained it and chilled it. Two hours later I had a dessert that reverberated with a slight touch––something that would require wiggle lines if rendered in cartoon form.

The oatmeal and pudding trials hint at one of the problems with expensive food additives. Once you buy them, it's hard not to justify the expense by complicating every meal with the new substance, even when uncalled for. Unthrilled with my results, I called a friend who happened to be conducting her own experiments with xanthan gum (these things are nothing if not trendy). She suggested that I add a pinch of the powder to my afternoon smoothie. This attempt, at last, approached success. When blasted with milk, bananas, honey, cinnamon and ice cubes, the gum turned an otherwise icy concoction into a chilled frozen treat––something to be eaten with a spoon instead of a straw.

Despite its tenuous claim to precious kitchen real estate, the availability of xanthan gum at supermarkets is proof that food-science geekery has leaked into the mainstream. If the fascination with superstar chefs brought us Rachael Ray's no-noodle lasagna, it also introduced Dufresne and Adria to those who couldn't afford trips to destination restaurants. If xanthan gum is any indicator, the home cook will soon be serving foamed meats at her next book-club meeting.

Perhaps at the root of our interest in foreign powders and gums lies something deeper than boredom or misplaced ambitions, something closer to the Enlightenment belief that scientific progress can solve all of our problems. And perhaps it can––we've yet to see. I'm just not sure that chocolate-chip cookies need solving.


Picture credit: Electronic Journal of Polish Agricultural Universities

(Molly Young is a writer living in New York. Her last article for More Intelligent Life was a review of the Met's "Model as Muse" exhibition.)