einfachbier,
From The Oxford Companion to Beer
a now antiquated German federal beer tax category that was abolished effective January 1, 1993. Literally, the term meant “simple beer” and referred to a beer with an original gravity—measured in degrees Plato—of 2°P to 5.5°P. See plato gravity scale. For an explanation of the old and the new German beer tax law, see vollbier.
This definition is from The Oxford Companion to Beer, edited by Garrett Oliver. © Oxford University Press 2012.