How tap water affects home espresso machines
Water and your home espresso machine
This site explains what water hardness is, how to find the number for your tap water, and what machine makers say about water and descaling. Each page defines its terms first, then gives details and exceptions. Your own machine's manual always comes first.
All the water notes
- Why water matters for a home espresso machine
Water can change mineral buildup inside a home espresso machine and the taste of the shot. Here's what two makers say and where hardness comes in.
- What water hardness means: GH, KH, TDS and ppm
GH, KH, TDS and ppm explained for beginners, with the USGS hardness classes and what makers' water guides do with these numbers.
- How to find your tap water hardness
Where to get a reliable hardness number for your home water: your supplier's report, the supplier itself, test strips and TDS meters, and what each tells you.
- What limescale is and why makers warn about it
Limescale is a chalky mineral deposit. Here's what it's made of, how it forms, and what two espresso makers say it does inside a machine.
- What machine makers say about water in their manuals
Two espresso makers give nearly opposite water advice. Here's what each one says to use and avoid, and how to find the rule for your own machine.
- Descaling: follow your maker's manual
How often to descale and with what depends on your machine. Here's what two makers say, how cleaning differs from descaling, and where to check.
- Tap, filtered, bottled and softened water compared
How tap, filtered, bottled, reverse osmosis, distilled and softened water differ, and what two espresso makers say about each type.