Xanthan is a natural gum produced by the fermentation of sugar with friendly bacteria. The bacterium used is Xanthomonas campestris, hence the name xanthan gum. Because bacteria produce the gum xanthan is known as a biogum.
The sugar most commonly used for the fermentation process is corn syrup which is mixed with the bacterial starter and treated with nitrogen and trace elements and allowed to ferment.
When fermentation is complete the syrupy broth is pasteurised to kill the bacteria. After filtering and washing the resulting solids are dried and ground to produce the gum.