I saw this on a Faust Facebook post. I'm guessing "Beery." Wir wünschen Euch allen schöne Weihnachten, ruhige und bierige Tage sowie alles alles Gute für 2017, vor allem Gesundheit! Zum Wohl, Euer Faust-Team!
Not unusual for breweries, brewers and beer bloggers etc. to sign off on newsletters or emails with "Mit bierigen Grüßen". I've always found nothing wrong with that, even if it pushes its user into the slightly dopey category.
I know it pops up every now and then, but I still do not think that it belongs to the normal vocabulary. Outside the beer world, you won't hear this world, and pretty much everyone would think it is kinda "weird". I am not saying it is "wrong", it is just part of a particular set of words of a specific group, "beer people".