First, a brief definition of xanthan gum. Xanthan gum is produced by the fermentation of glucose, sucrose, or lactose by the Xanthomonas campestris bacterium. It was developed in the United Staes in the early 1960s and approved for use in food in 1968. It is used in many foods, including commercial salad dressings, to stabilize the emulsion and suspend herbs and spices in a mixture. It is also used in toothpaste as a binder and in ice cream to help enhance the mouthfeel and add creaminess to the texture.
Xanthan gum just may be one of those ingredients that sounds worse than it is. Its reputation is often associated with other, more sinister chemicals, probably due to its ubiquitous use in many processed foods. ( This article by the Ideas in Food folks is a great introduction to xanthan gum.)
I checked the ingredient lists of a few plain commercially available vanilla ice creams and discovered that most national brands use some form of stabilizer, usually xanthan gum, guar gum and carob bean gum. The only exception in my limited sampling was Häagen-Dazs, which has no gums whatsoever.
One of the things xanthan gum does is help to prevent the formation of ice crystals, which is key to a rich, creamy, smooth ice cream. So should you add xanthan gum to your homemade ice cream? I've never tried it but I feel it's worth experimenting with. eHow has a tutorial on how to add it to existing recipes, with a simple formula of one quarter teaspoon of xanthan gum to one quart of ice cream base. Also, it occurred to me that the beloved and famous Jeni's Ice Cream recipe uses cream cheese as one its base ingredients and cream cheese is often stabilized with xanthan or guar gum. (Jeni's commercially sold ice creams do not list cream cheese in their ingredients.)
Guar gum is another popular emulsifier and is thought to be better in cold foods, although you have to be careful with higher acid ingredients, like lemon. Both xanthan and guar gum are not easily digestible for some people, so be sure to check before serving it to guests. Vegans and dairy-free folks take note: The addition of xanthan gum is a great way to make ice cream from non-dairy ingredients like soy, hemp, almond or coconut milk.
Have you ever used xanthan (or guar or carob bean) gum in your ice cream?
Related: How Can I Make Creamier Ice Cream?