i'm slowly piecing together a little handwritten journal of brewing basics (think sean connery's holy grail notebook in the last Indy movie) (I also consider that franchise a trilogy). i just do a single infusion mash, which as I understand it is essentially another name for a saccharification rest. So, Sacch rest - 148-156ish - gelatinize starches, extract sugars, etc. I know i've heard of an acid and protein rests, but are there any others? are there specific instances when these rests are useful or are they largely throwbacks to historical brewing and undermodified malts?