title_body: How do I tell if I poured a stout correctly?
upvoted_answer: Like most beers, the main thing is the height of the foam on top of the beer.  It's largely a matter of personal preference; the only considerations I'm aware of are:
  
  
  Bottle-fermented beers should be poured slowly and all in one go to prevent yeast from going into the glass (and, to that end, leave half a finger of beer in the bottle).
  Unless it's an unfiltered wheat beer, in which case the yeast is meant to go in the glass.  Also, hefeweizens like this should go for a little larger head than normal (2-2.5 fingers).
  Or if it's a nitrogenated beer (Eg, Guinness with a widget), you should simply upend the can or bottle into the glass
  Otherwise, most people aim for about 1 finger-width of foam.  As long as you have at least some head and it doesn't overflow the glass, you're pouring fine.