What is Xanthan Gum?
Xanthan gum is a white to the tan colored powder used in many food products.
How is Xanthan gum made?
Xanthan gum is made from the fermentation of carbohydrates (sugars). The bacteria strain Xanthomonas campestris is fed with carbohydrate and metabolizes the sugars into a liquid solution. The solution is mixed with alcohol (ethanol or isopropanol) which causes the gum to separate from the water. The gum is then rinsed, dried and ground.
Is Xanthan gum kosher?
Every fermentation process causes kosher concerns due to the ingredients that are used to make the fermentation more effective.
The alcohol is also a kosher concern. Ethanol can be derived from grapes (nesech), lactose (dairy), wheat and barley (chometz).
Answer
Xanthan gum must have a reliable kosher certification.
Source: ok.org