I made a jus gras according to the recipe in Modernist Cuisine at Home. This calls for initial thickening of stock by adding xanthan gum to the liquid while processing with an immersion blender. In terms of taste and texture, it worked well. But I was surprised: as soon as the gum hit the whizzing stock, the mixture turned ivory-white. (The stock was medium brown to begin with.) Is this normal with xanthan gum? I'm using Bob's Red Mill brand, if that matters. Is there a way to produce the same clean GF thickening effect while retaining a more natural-looking brown color?