From an easthetic stand point #12 catches my eye more, but #18 makes more sense re: the brewery. I can already amagine the number of questions I would be asked regarding who the man on the label was. As far as #18 goes, you did not need to copy the Prussian flag exactly, just the tone and style of the eagle which I think you did very well. It has a nice old world, dominating nature to it that contrasts the structure and shades of the label very well. If anything I would take another look at the flag, or at
#17. This image seems more dominating than the one you went with.
Lastly, play around with not using the word Brewery on the label. You don't see the word brewery on too many beer labels, nor do you see the word winery on too many wine labels. I think the contents of the bottle will suffice in communicating what we do.
Keep up the great work!