Does Hard Water Affect Coffee and Tea Taste?
How water hardness changes the flavor of coffee and tea, and what baristas recommend.
Water is 98% of your coffee
The Specialty Coffee Association recommends water with 50-175 PPM TDS and hardness between 17-85 mg/L (1-5 GPG) for optimal extraction. Water that is too soft under-extracts (sour, thin). Water that is too hard over-extracts (bitter, flat) and leaves scale in your machine. Most hard water cities are well above the ideal range.
The espresso machine problem
Scale buildup in espresso machines, pod machines, and kettles is accelerated by hard water. A $500 espresso machine can be destroyed in 2-3 years without descaling. Even with regular descaling, performance degrades. Professional coffee shops in hard water cities always use filtration.
The fix
For coffee specifically, a simple carbon + ion exchange pitcher filter (like a BWT or Peak Water pitcher designed for coffee) is the easiest solution. For whole-house treatment that also improves coffee, a softener brings hardness into range. Check your water hardness against the SCA recommendation.