I tried to make seitan last night using oil and gluten, and after it was done it had a grainy consistency and didn't hold together at all. Is there some sort of magic done by the water? How much water do I need?
I've never made seitan, but just like when making bread, gluten needs water to activate. I don't know the precise amount. Oil, if anything, has the opposite effect, coating the gluten molecules and keeping them from linking up, which is why we use fat in pastries to keep them from getting tough.
There are four major types of proteins in Wheat: gliadin, glutenin, albumin, and globulin.
What we think of gluten doesn't actually exist in wheat; it develops in flour when it is hydrated with water and gliadin and glutenin proteins bond together to make what we call gluten. So that is the magic. Oil is chemically very different so that is why it was weird.