Like Denzelmum, when I want to use soy instead of dairy, I just substitute with soy. Sometimes I will thin it a bit as I think soy is a tad 'thicker'. ie I have a coconut bread recipe which calls for 3/4 cup of milk. My sister, who gave me the recipe, always substituted that for 1/2 cup soy & 1/4 cup water. I've always just done as she suggested, with lovely results.