Same beans, same grinder, same recipe, different city, different coffee. It is almost always the water.
How much supplies vary
Very soft — the Pacific Northwest, much of New England and parts of the Southeast. Hardness under 50 ppm.
Very hard — much of the Southwest, Texas and the Midwest, where water drawn through limestone often exceeds 250 ppm and can pass 300.
That is a fivefold difference or more, and it changes extraction fundamentally.
What each does
Soft water extracts less. Coffee tastes thin, sour and hollow, and light roasts suffer most.
Hard water extracts harshly and, with high alkalinity, flattens acidity. Coffee tastes dull, chalky and flat.
Why it dominates
Every other variable travels with you. The grinder setting, the ratio, the technique — all the same.
Water is the one thing you cannot pack.
Other contributors
Altitude changes boiling point — around 3 °C lower per 1,000 m (about 1 °F per 500 ft). In a mountain town, water boils cooler and extracts less.
Ambient humidity changes how coffee grinds.
Different milk, which varies more between countries than people expect.
What to do while traveling
Buy bottled water with a low bicarbonate figure. It is the fastest fix.
Adjust the grind — finer in soft water, coarser in hard.
And at home
If your coffee has always been slightly disappointing, test the water before buying anything.
Last reviewed 30 October 2026