I do a single batch sparge and have eff's in the high 80's to low 90's. I also end up collecting about 8 gal of wort to boil. Since I know with my pot I boil off 1.5 gal/hr I plan my boil time to end up with the proper OG for the recipe. I could adjust the brewhouse efficiency in my calculator (right now set at the default 75%) but this way I end up with 2 or 3 more quarts of beer. Is that a bad thing?
Is there a problem saving and freezing any additional wort to use as a starter? Getting a little OT here, but I would love to not buy DME anymore. That crap is expensive!