Xanthan can indeed be used uncooked. For example, I thickened watercress pesto with a bit of xanthan gum powder in the vitamix today. It is just thick enough to paste a scallop seared with fennel pollen on a crostini. It will be finished with a grapefruit glaze. There are exact measurements for use on Modernist cooking. I free handed it in the blender until I was satisfied with its consistency however.