Edinburgh's water is genuinely hard and mineral-dense across nearly every measure at once — calcium, sulfate, chloride, and bicarbonate all sit at meaningfully elevated levels together, closer in overall mineral load to Dortmund's dual-sulfate-chloride profile than to any single-mineral-dominant water like Burton's or Dublin's. That broad mineral richness gave historical Edinburgh brewers a genuinely robust water to work with, capable of supporting a big, malt-forward beer without needing much correction.
A profile with no single standout, but real overall weight
The classic reference figures for Edinburgh water: calcium 100 ppm, magnesium 25 ppm, sodium 55 ppm, sulfate 140 ppm, chloride 65 ppm, bicarbonate 225 ppm. Nothing here reaches Burton's sulfate extreme or Dublin's bicarbonate-to-calcium imbalance, but the combination of moderately-high everything gives the water real presence — enough sulfate to sharpen perceived bitterness somewhat, enough chloride to round out body, and enough bicarbonate alongside a decent calcium reading to buffer a moderately dark mash comfortably. It's a water profile built for substance rather than for pushing hard in any single stylistic direction.
Why this suited malty Scottish brewing specifically
Scottish Ale's own low-attenuation, malt-forward, minimally-hopped character developed under real historical constraints — a cooler climate less suited to reliable hop cultivation pushed Scottish brewing toward malt as the primary character-carrying ingredient, and Edinburgh's mineral-rich, buffered water gave that malt-forward approach a genuinely supportive base to work from rather than fighting against a very soft or very hop-accentuating water supply the way some other traditions had to contend with.
Using this profile
These numbers describe a historical approximation, not a live reading of Edinburgh's current municipal supply — confirm your own water before assuming it matches. Building toward it from a softer source generally means a combined gypsum-and-calcium-chloride addition to lift both sulfate and chloride together, plus enough bicarbonate to support a moderately dark mash comfortably; see the Scottish Ale style guideline for the malt-forward beer this water historically paired with. A brewer building this profile up from a softer starting water should expect to add real quantities of more than one salt at once, since no single addition covers calcium, sulfate, and chloride together the way this water's own broad mineral spread does.