All-grain brewing opens up a huge realm of possibilities for the malt profile of your beer.  Of course it comes with the cost of an extra step of complexity with the "mash".  Mashing is a process that is described by John Palmer in "How to Brew" as "the hot water steeping process that hydrates the malt, gelatinizes its starches, releases its natural enzymes, and converts the starches into fermentable sugars" (p.141).  More simply put, it's like making barley-sugar-water through steeping - just like tea.  In this post I will discuss the choice of the mash temperature and how it will affect the wort that you produce.