Why Your Water Matters More Than Your Beans

Coffee is roughly 98% water, which makes it a little strange that most brewing advice focuses almost entirely on the other 2%. Water chemistry changes extraction and flavor more than most people expect.

What matters in your water

• Total dissolved minerals: some mineral content is necessary for extraction - distilled water actually brews flat, under-extracted coffee. But too much, especially hard water high in calcium, can mute flavor and cause scale buildup in your equipment.
• Chlorine and off-tastes: tap water treatment chemicals carry straight through into your cup. If your tap water tastes off on its own, it’ll taste off in your coffee too.
• pH: water that’s too acidic or too alkaline can throw off extraction balance in either direction.

What to actually do

You don’t need bottled water or a water science degree. A basic carbon filter pitcher removes most chlorine and off-tastes while leaving enough mineral content for good extraction, and that’s enough for the vast majority of home setups. If you’re chasing competition-level precision, specialty brewing water blends exist - but that’s a rabbit hole, not a requirement.