Original quote from AZ IPA:
Originally Posted by AZ_IPA
mash efficiency is the conversion of your grains to sugars (you should be able to get above 90%).
brewhouse efficiency is usually your overall efficiency (% of available sugar that makes it into the fermenter).
check out braukaiser.com for great information on efficiency!
FYI, Kai Troester (Braukaiser) is a master at experiments, check out his site--great info.