Dortmund's water does something none of the other city profiles on this site manage: it carries genuinely high sulfate and genuinely high chloride at the same time, rather than one dominating while the other stays low. Sulfate and chloride pull perceived beer character in opposite directions — sulfate sharpens and dries, chloride rounds and fills out — and having both elevated at once produces a beer that reads simultaneously crisp and full-bodied rather than leaning cleanly toward either extreme.
Two minerals that usually trade off, both pushed up together
The classic reference figures for Dortmund water: calcium 232 ppm, magnesium 26 ppm, sodium 60 ppm, sulfate 120 ppm, chloride 60 ppm, bicarbonate 220 ppm. Compare that against Burton-on-Trent's water, which pushes sulfate to 820 ppm while chloride stays modest at 96 ppm — a lopsided profile favoring sharpness. Dortmund's sulfate sits considerably lower than Burton's, but its chloride runs meaningfully higher relative to that sulfate figure than Burton's does, producing a genuinely different balance rather than just a scaled-down version of the same idea. That's real, checkable water chemistry, not a vague regional flavor description.
The style this specific combination made possible
Dortmunder Export developed as a moderately strong, pale-to-golden lager with real malt substance underneath a crisp, clean finish — a style that reads neither as purely hop-sharp (the way Burton's water pushes English pale ale) nor purely soft and round (the way Munich's low-sulfate water pushes Bavarian lager), landing instead in a genuine middle ground that Dortmund's dual-mineral water supports directly. High calcium alongside meaningfully high bicarbonate also gives this water real buffering capacity, useful for a moderately strong, moderately pale grain bill that needs enough alkalinity to avoid an overly acidic mash without needing anywhere near Dublin's extreme alkalinity.
Using this profile
These numbers are a historical approximation rather than a live feed from Dortmund's current municipal supply — check your own water before assuming a match. Building toward it from a softer starting water typically means additions of both gypsum (for sulfate) and calcium chloride (for chloride) in more balanced proportion than a purely sulfate-forward Burton-style build would use; PeriodicDeck is a useful reference if you want the underlying chemistry of calcium, sulfate, and chloride explained before adjusting your own brewing salts.