Monday, August 05, 2019

all hail xanthan gum!

As I learn more about how the keto diet deals with things like carby thickeners, the more fascinated I become. In particular, I've been learning about xanthan gum which, in keto breads, is a thickener that takes the place of gluten—the stretchy, proteinaceous substance that gives bread its flex, bounce, and stretch (and, by extension, stretchy bubbles).

I recently ordered two small bags of xanthan gum in preparation for when I do finally attempt to make some keto bread, and I decided to use some of the gum when I made some egg-drop soup for myself the other night.

Very impressive stuff. Xanthan gum, which is derived from a bacterium (Xanthomonas campestris), should be used in very small quantities, as I found out while making egg-drop soup. A mere teaspoon into nearly a liter of soup thickened the entire thing within seconds. This makes xanthan gum much more effective than cornstarch.

The carb profile for xanthan gum can be a bit misleading: there are 6 grams of carbs per 7 g of gum, but there are zero net carbs in xanthan gum. If I ever decide to make a less carby version of my generic Chinese stir-fry sauce, I'll replace the cornstarch with xanthan gum.



4 comments:

Charles said...

I knew that xanthan gum is a thickener, but I never knew that it could be used as a gluten substitute. I suspect that there might be a difference in the texture of the final product, but there's only one way to find out.

We actually have some agar agar at home that we use for thickening. I wonder if that would also work (a quick internet search says "yes"). The only thing that gives me pause is that xanthan gum and agar agar are primarily used as thickeners, whereas gluten is not a thickener (it's the starch in flour that thickens, not the proteins).

Actually, come to think of it, why would you need to replace gluten in a keto diet? Isn't it the carbs you have to worry about?

Kevin Kim said...

If I'm not mistaken, a keto diet is supposed to be moderate in protein along with being carb-minimal. According to Wikipedia—and you may already know this—the diet was originally developed to combat epilepsy. Apparently, moderating protein intake while minimizing carbs has proven effective in reducing incidence of epilepsy in many patients. The diet has the familiar low-carb marks of the Atkins regime, so I guess it was only a matter of time before "going keto" became a thing outside the confines of epilepsy patients. That might at least partially explain the impulse to switch out gluten for something else.

Meanwhile, all hail agar agar!

Charles said...

I was not, in fact, aware of that. I only really know about keto from some friends of mine, who presented it as more of a "caveman diet." I think they might have been just going off the process of ketosis, which is encouraged by a low-carb diet. But I think that's something different from what you're talking about (I just looked on Wikipedia and saw that it describes the keto diet as "a high-fat, adequate-protein, low-carbohydrate diet").

Still, eliminating gluten for the sake of eliminating protein seems a bit overkill to me, since gluten only makes up about 13-14 percent of flour even in the highest of concentrations. If the goal is to stick to an adequate protein intake, it would seem to be easier and more efficient to just moderate consumption of meat or other protein sources.

But I'm still curious about this keto bread, though. Some recipes I've seen use things like almond flour or other nut/seed meal for the flour component. This all sounds like heresy to a traditional baker like me, but I can't help being curious.

Kevin Kim said...

I'm going to try making some keto bread tonight, actually. If it works out, I'll be using it in place of a bagel for tomorrow's lunch of smoked salmon, cream cheese, and capers. Photos to follow. Could be glorious, could be a disaster. (I bought what was labeled as "almond flour," but apparently, it's actually almond meal. The keto crowd says this just means the bread will end up with a rougher texture. In such situations, chefs like to spin the roughness positively by calling the results "rustic." Heh.)