Originally Posted by Daparish
Hmmm, did not know that. So in theory, I could've added the 4 lbs of DME at flameout and still hit my OG?
Sure. So long as it gets fully dissolved, that's all you need to do with extract. It's already been boiled once when it was made. You'll get some extra bitterness from your hops if you don't adjust the recipe to account for the lower concentration in the boil, but that's not hard to do. Or don't if you don't want to bother. I adjust because then I shell out for a little less hops per recipe to get the same beer.
It's easy to tinker with recipes in beersmith to do this. Enter the recipe as it is, then change the extract to be added after the boil. Then readjust the bittering hops until they're back to the IBU's they were at before you changed the extract timing.
I did a writeup on using Beersmith to convert all grain recipes to partial mash with the goal of having the partial boil be a smaller version of the OG's wort, and then adding LME at the end to compensate for the top up water due to the partial boil. Here it is if anyone's interested: http://www.homebrewtalk.com/f12/converting-recipes-partial-mash-partial-boil-beer-smith-142244/