If you've baked with gluten free flours for any length of time, you undoubtedly learned very quickly that they don't hold together in the same way that wheat flour does.
Despite the best of intentions, you really can't substitute a cup of rice flour for a cup of wheat flour to make a loaf of bread. That certain something special will simply be missing.
Similarly, your favorite cookies may turn into a burned, crumbled mess!
The gluten in wheat is what binds doughs beautifully; it provides the sticky cohesion that bakers and chefs love so well.
In order to achieve the same effect with gluten free flours, resourceful gluten free bakers typically rely upon a well known food thickening agent called xanthan gum. Adding this substance to batters and doughs helps create gluten free baked goods and treats with the perfect level of viscosity. They hold together with style.
So, what's the catch?
It might not be time yet to bust out the theme music from the movie "Jaws"... but as it turns out, there is a lot you may not know about the xanthan gum in your cupboard or refrigerator.
Xanthan gum is a polysaccharide made from the coat of a tiny microorganism called Xanthomonas campestris. Companies like Bob's Red Mill make it by fermenting glucose, sucrose or lactose with this bacterium, and then use isopropyl alcohol to "precipitate" it from the growth medium. It is later dried and ground into a powder.
These companies use the xanthan gum powder in a wide variety of products. It works as a thickener or stabilizer for a diverse range of products and needs ranging from ice cream to cosmetics to thickening mud for drilling. Xanthan significantly increases the viscosity of liquids and in most foods it is used at a concentration of .5%.
Here's something important that food manufacturers don't really advertise about xanthan gum:
Your xanthan gum has the potential in itself to trigger allergic responses if you happen to be sensitive to its growth mediums.
Do you know what the growth mediums for xanthan gum ARE? Do you?
Because until today, I didn't.
The growth mediums are: CORN, DAIRY, WHEAT, SOY
Yes, that xanthan gum you're using in your gluten free baking may actually have been derived from WHEAT.
In fact, it probably is!
I called Bob's Red Mill today and spoke with a representative, because I wanted to make sure that the xanthan gum I use for my gluten free baking was not grown from a soy medium. I have an allergy to soy that I try to be really respectful of, and I strictly avoid all possible exposure to soy.
Imagine my shock to hear straight from the representative,
"Oh no, you have nothing to worry about. We don't use soy. Our xanthan gum is created using wheat starch."
Dumbfounded, I responded - "But, it's supposed to be gluten free! It says so right here on the package."
"Oh, by the time the bacteria has done its work there are zero wheat proteins remaining," he assured me. "We grow it from wheat starch but it is gluten free by the time it gets to you."
I wondered how he could be so sure.
The label on the bag of Bob's Red Mill gluten free xanthan gum states:
"Bob's Red Mill Products Labeled Gluten Free are batch tested in our quality control laboratory. We use an ELISA Gluten Assay test to determine if a product is gluten free." (Emphasis added.)
Which means, in sum, that Bob's Red Mill is deciding for itself if its products are actually gluten free. There is no independent lab involved, no third party testing.
Here is a quote from AllAllergy.Net which sums up my concerns as a gluten free baker:
"In the U.S. there are 2 major suppliers of xanthan gum. One uses soy as the fermentation medium while the other uses wheat. Residual wheat gluten has been detected on the xanthan gum made on the wheat substrate."
If residual gluten has been detected in even *some* batches xanthan gum grown from the wheat starch medium, what guarantee is there that ALL packages of xanthan gum from any company - including Bob's Red Mill - are truly gluten-free? How often are they actually batch testing? Do they test every week? Every month? Once a year?
More importantly... can folks with a heightened sensitivity to gluten REALLY rest assured that they will not have an allergic response to the xanthan gum that they are baking with?
If you suffer from a known allergy to gluten, corn, dairy or soy I highly recommend calling the manufacturer of the xanthan gum product you like to use in your baking to find out exactly what medium they are growing it from.
You might be shocked to discover, as I was, that your friendly little package of xanthan gum is actually grown from a product to which you are highly sensitive... and that the company itself is doing its own ELISA testing without an external quality control.