Water and beer
Date
Below 5 dH is the perfect water hardness to brew most types of beer in Germany.
By the way, the water hardness in Munich is a lot higher with over 13,6 dH. Therefore, the Munich breweries have deep wells where they can reach softer water, like Giesinger Biermanufaktur & Spezialitätenbraugesellschaft mbH did 2020. Their well is around 150m deep.
Sources: https://www.hopfenhelden.de/bierwissen-craft-beer-brauwasser/
