I dough in with a typical 1.3-1.5 qts/# to hit my conversion rest temps. Then I add the remaining amount of
I would like to nip this one in the bud before flbrewer assumes that the first step in mashing is referred to as "doughing-in." The term "dough-in" is one of the most misunderstood terms in home brewing today due in large part to its misuse on brewing forums. The first step in mashing is technically called "mash-in" or "mashing-in" (the term is also used in distilling).
A dough-in is a specific type of mash-in. It is the first step in a multi-rest mash that usually includes sub-saccharification rests (i.e., glucanase, protease, and/or acidulation rests) in addition to one or more saccharification rests. The reason why the step is called dough-in is because the mash has the consistency of dough after the process is complete. Unlike a typical single infusion mash-in where hot strike liquor is infused with the goal of hitting a saccharification rest temperature, relatively cool (58F) water is used in a properly executed dough-in, and the mash is kneaded like bread dough as water is slowly added. The purpose of a properly executed dough-in is to thoroughly wet the grain while limiting the amount of standing liquid. We dough-in in this type of mash in order to improve enzyme effectiveness and allow for the addition of multiple hot liquor infusions without making the mash too thin.
The takeaway here is that if one is infusing hot liquor into dry grist in order to hit a saccharification temperature, one is mashing-in, not doughing-in. While the book is somewhat dated, Greg Noonan covered doughing-in in Brewing Lager Beer.