After doing more reading it sounds like it starts out with a starch and the starch converts to...something else. I am not smart in chemistry. I personally don't feel like the vodka water makes my fabric stiff. If I was starching something that really needed to be starched, like bias edges or something, I would probably use Niagara spray starch. But for pressing seams, I like the vodka water. I don't use a scent though, and I have a feeling the whole reason for the vodka is to disperse the scent and act as a preservative for it.