Water for Espresso: Hardness, Alkalinity, & Taste
Water decides how much of the coffee dissolves—and whether your machine scales up. Here’s the simplest way to get great flavor without headaches.
Targets
- Alkalinity (KH): 40–80 ppm. Buffers acidity; too low = sour/spiky; too high = muted/flat.
- Hardness (GH): 40–80 ppm. Impacts extraction, crema, and mouthfeel; too high can scale.
- Temperature: Water recipe doesn’t replace dialing in; keep brew temp in your usual range.
Quick recipes
1) Full control (distilled/RO base). Start with distilled or RO water. Add a measured amount of bicarbonate (KH) and magnesium/calcium salts (GH) per your target. Mix thoroughly; store in a clean, labeled bottle.
2) Tap water check. Use test strips or a small drop kit to measure your KH/GH. If KH is near 60 ppm and GH near 60 ppm, you may be fine to use as-is (taste and monitor scale).
Stability tip: Pick one recipe and stick with it for a few weeks. Changing water mid-dial-in moves the goalposts.
Tuning by taste
Brighter than you like? Increase KH slightly (e.g., +10 ppm) or pull a slightly longer ratio.
Flat or chalky? Reduce KH a touch or lower GH toward the middle of the range.
Thin body, weak crema? Nudge GH upward within the safe range and check grind fineness.
FAQ
Will “perfect” water fix channeling?
No—distribution and tamping drive flow. Water mainly affects extraction profile and taste.
How often should I descale?
Depends on your recipe and machine. If you keep GH/KH in range and use filtered sources, descaling slows down significantly.
Do I need a lab kit?
No. Start with strips and a simple recipe; upgrade only if you want finer control.