Guar Gum versus Xanthan Gum… what's the difference?
I am asked a lot if it’s okay to substitute guar gum for xanthan gum in my recipes. The answer is “yes”. They are pretty much interchangeable, one for one. Many brands of xanthan gum are a derivative of corn (except for Authentic Foods xanthan gum), so those with corn allergies will want to use guar gum in my recipes when I call for xanthan gum. But please note, there are subtle differences. To illustrate this subtlety, I have turned once again to my trusty Classic Chocolate Chip Cookies recipe. I made one batch with xanthan gum (as the recipe instructs) and one batch with guar gum. All other ingredients were EXACTLY the same. See the photos below. The top photo are the cookies made with xanthan gum, the bottom, with guar gum. Both were delicious, but there was a slight difference in texture.
The cookies made with xanthan gum (top) are slightly chewier, with more cracks in the surface. The cookies made with guar gum (bottom) are more domed, with fewer splits in the surface and a very slightly denser consistency. One is not better than the other. I found the cookies made with guar gum crumbled a bit more, but that’s the way the cookie crumbles! The one notable difference I should add is that the cookies made with guar gum caused some gastric distress (that’s right, that’s code for “GAS”). I looked into this and sure enough, gas is a side effect of guar gum, but one is assured that after several days of ingesting it, this will settle down.
So what are these vegetable gums, and why use them in the first place? Both xanthan gum and guar gum are used in gluten-free baking to help mimic the structure traditionally provided by gluten (protein) in wheat flour. They add viscosity, and really help keep the baked goods together (binding), as well as preventing them from drying out too quickly. In the old days, I tried baking gluten-free without xanthan gum, out of some sort of misguided rebellion (I didn’t need that 1/4 teaspoon of powder!) I have since come to my senses. After all, it really is magic powder. And a little bit goes a long way… so though it might seem rather spendy, a bag of xantham gum or guar gum should last you many months. Keep it tightly sealed in the fridge.
But back to what they are…. two apt discriptions http://www.wisegeek.com/what-is-xanthan-gum.htm http://www.wisegeek.com/what-is-guar-gum.htm
In sum: you can use either xanthan gum or guar gum in my recipes. Guar gum is less expensive, but it might give you gas until you get used to it. Up to you.