Xanthan gum (or simply xanthan) is a relatively recent product, used since 1969. It was developed in the United States as part of a programme to find new applications for maize, as it is produced by fermentation of the sugar, which can be obtained previously starting from cornstarch, by the bacterium Xanthomonas campestris. Xanthan gum is simply a gelling agent, i.e. a natural product that allows us to modify the original texture of a liquid to achieve a greater density. It comes in a powder and its dosage depends on the density of the original liquid and the texture we want to obtain.
Its easy dissolution, stability at almost any temperature, and the fact it does not confer flavour but gives a pleasant or, at least, neutral taste sensation, means that it is used to increase viscosity in countless sauces and commercial products.
In cookery, xanthan gum has very interesting applications. On the one hand, it can be used as a thickener to thicken sauces in a simple way, without the flavour sometimes added by other traditional thickeners (flour, tapioca, potato...), which tend to be much heavier. In addition, very colourful effects can be achieved with it. In transparent or translucent liquids, it can be used to keep small pieces of solids in suspension, while not producing any colour: for example: with a fruit salad in a glass of fruit juice, small pieces of fruit can be distributed throughout the volume of the glass, as the density of the liquid prevents the pieces from rising to the surface. In fact, this effect was used commercially in drinks before renowned chefs began to use it. What is amusing is to introduce coloured liquid droplets into transparent or translucent liquid. The different densities do not mix (or take a long time to do so) and the density of the xanthan gum prevents the droplets from rising, so they stay suspended inside the liquid.
My friends Ferrán Adrià and his brother Albert are the chefs who have researched and written most about this gelling agent, one of the products we can now begin to use in a spherical way. Stepping further into the world of contemporary cuisine, they have even marketed a Spherification MiniKit (with alginate, gluco, xanthan gum, agar and Lecite, a soy lecithin-based emulsifier), with which you can experience – even at home – all those textures offered by the more daring chefs. These starter kits for molecular home cooking can create a wide range of dishes with great diversity of flavour and texture, based on the spherification technique.