This is too powerful.
The one beer(scroll) to rule them all!
If thats the problem, then kegs or even half of the available kegs could be refilled only once in the region where the spell is cast, instead of the whole vicinity.
The fun thing is that a lord can announce having such scroll to all advies he can contact, asking them to come to his region and hunt the rogues there.
As an extra reward for riding the region of such, the advies are given free beer by the use of this scroll.
Obviously a Lord could call a bluff and attract advies without having any scroll at all
