wort makeup and attenuation

[jrdunne (Joe Sr.)]

@brewinhard

If you repitched  a dry yeast from a previous fermentation (slurry) with poor aeration, then that could definitely be your issue. While dry yeast reportedly does not need oxygen in its initial use, subsequent generations will most definitely be oxygen deprived and in great need of proper aeration to fully attenuate your next batch of wort.

Why would a slurry from an initial pitch of dry yeast be any different from a slurry from a Wyeast pitch?