IIRC if you mash corn with malt enzymes it turns to maltose. Someone correct me if I am wrong.
Interesting topic about the ginger being mashed. I use a lot of ginger, mostly all at knock out and whirl pool. One thing I have seemed to notice with ginger is the longer you boil it the "spicier" (IOW hotter) it becomes. I am planning on doing some actual tests on that soon to see how rue it is.
I just brewed a honeyed ginger ale with lemon rind a few weeks ago and it is pretty tasty, though perhaps a little over the top on the ginger.