Bauer = B(r)auer = Brewer!

The sign for breweries in Germany was ...

the brewers star: https://beerconnoisseur.com/articles/brewers-star

The Brewer’s star was the official insignia of the Brewer's Guild as early as the 1500s, and its association with beer and brewing can be traced back even farther. Digging deeper into the past you’ll find that what is today a star didn’t start out that way. In about the 15th century, when alchemy – a medieval science and speculative philosophy that aimed to turn common elements into precious metals – was still a thing, and triangles were symbols that were strongly associated with it. One triangle, pointed skyward, symbolized fire; another triangle, pointed at the earth, symbolized water. Superimposed on one another, they achieved balance.

https://www.schlenkerla.de/biergeschichte/brauerstern/html/ausschankzeichene.html

4.3.3 Why the hexagram as brewing sign? As mentioned earlier, literature often describes the brewing star as alchemistic symbol, which symbolises the for brewing necessary elements [117] . However it seems unlikely that at the general low level of education in mideval times [118] brewers would have known about the alchemistic significance of the hexagram. In addition, brewing used to be a duty of women and were then adapted by monks and later tradesmen in the city. As described earlier, the clerus had used the beersign in Regensburg as tapping sign. It is highly unlikely that monks would use alchemistic symbols for anything, especially so as Pope Johannes XXII condemned alchemy in 1317 [119] .

Moreover, alchemy existed all over Germany, while the brewing star can in this form only be found in franconia and nothern bavaria. Furthermore the question arises, how the not very well regarded and by the church pursuited alchemists suddenly could have become accepted brewers in cities and even council members. Last but not least the comparison between brewing beer (turn water into beer) and alchemists (turn crude metal into precious metal) is somewhat strange from a mideval point of view: Beer was - other than wine - not a precious drink, but everyday nuritment for commoners.

All combined, the theories on the connection between alchemy and brewing seem to based largely on superficial, modern assumptions. But what other reasons could have lead to the usage of the hexagram as brewing symbol?

A possible answer to this question could be found in the second meaning of the hexagram: Its usage as protection symbol [120] . As described earlier, the hexagram in mideval times a sign against bad luck, demons, weapons and fire. The shielding of demons was - because of the in chapter 2.1 described misconseption - quite important for brewers, and also the need to avert combustion. Hazardous fires are reported frequently in malt houses and breweries [121] . The sexangle can hence also be found in the emblems of other crafts which were confronted with fire, such as chimney sweepers [122] . In addition, the Jews were also familiar with the hexagram as fire protection symbol [123] .