Why does my coffee taste salty or metallic?
Updated
Short answer
A salty, metallic or mineral taste almost always comes from the water, not the coffee. Change one thing per brew, in this order: Lower your water's mineral content, then try a different water profile.
What it means
Salty, metallic or mineral flavours almost always come from the water. Too many dissolved minerals — or the wrong mix of them — sit on top of the coffee and flatten everything else.
It's the one fault where the water leads. Bring the mineral content down first; if that doesn't clear it, the water itself needs changing.
Pour over: what to change
Pour over (V60, Chemex, Kalita Wave, Origami, Orea). Try these one at a time, in this order — move on to the next only when the one before hasn't fixed it.
- 1
Lower your water's mineral content
About 20% fewer minerals — 150 to 120 ppm, say. Softer water extracts more gently, and with less buffering on the acidity it reads cleaner and brighter.
- 2
Try a different water profile
Last resort. A new water changes several flavours at once, which makes it hard to tell what did what — so it comes after every single-variable change has had its go.
Immersion: what to change
Immersion (AeroPress, French Press, Hario Switch). Try these one at a time, in this order — move on to the next only when the one before hasn't fixed it.
- 1
Lower your water's mineral content
About 20% fewer minerals — 150 to 120 ppm, say. Softer water extracts more gently, and with less buffering on the acidity it reads cleaner and brighter.
- 2
Try a different water profile
Last resort. A new water changes several flavours at once, which makes it hard to tell what did what — so it comes after every single-variable change has had its go.
Cold brew: what to change
Cold brew. Try these one at a time, in this order — move on to the next only when the one before hasn't fixed it.
- 1
Lower your water's mineral content
About 20% fewer minerals — 150 to 120 ppm, say. Softer water extracts more gently, and with less buffering on the acidity it reads cleaner and brighter.
- 2
Try a different water profile
Last resort. A new water changes several flavours at once, which makes it hard to tell what did what — so it comes after every single-variable change has had its go.
Worth knowing
- Very occasionally, salty reads come from extreme under-extraction on a very light roast. If the cup is also sour and thin, try the sour coffee guide first.
Change one thing at a time
It's tempting to grind finer and raise the temperature and pour differently. Then the next cup is better or worse and you don't know why. One change per brew is slower on paper and much faster in practice. The full dial-in guide covers the order to fix things in when there's more than one problem.
Questions
Why does my coffee taste salty or metallic?
A salty, metallic or mineral taste almost always comes from the water, not the coffee. Salty, metallic or mineral flavours almost always come from the water. Too many dissolved minerals — or the wrong mix of them — sit on top of the coffee and flatten everything else.
How do I fix salty or metallic coffee?
Change one thing per brew. On a pour over: Lower your water's mineral content, then try a different water profile. On an AeroPress, French Press or Hario Switch: Lower your water's mineral content, then try a different water profile.