01 — What’s Really in Your Water (And Why Your Coffee Cares)
You sourced the beans. You dialed in the grind. You nailed the pour. And still — something’s off.
Nine times out of ten, it’s the water.
Coffee is 98% water. Which means the water you use isn’t just a vehicle for your coffee — it is your coffee. And most of us never think twice about it.
What’s Actually in Your Water
Water isn’t just H₂O. Tap water carries dissolved minerals — primarily magnesium, calcium, sodium, and bicarbonates — and the balance of those minerals determines how well your water extracts flavor from coffee grounds.
The key measurements to know:
- TDS (Total Dissolved Solids) — the total concentration of minerals in your water, measured in parts per million (ppm). The Specialty Coffee Association recommends 150 ppm as the sweet spot. Too low (like distilled water) and your coffee tastes flat. Too high and it tastes harsh or chalky.
- Magnesium — the mineral most responsible for extracting bright, complex flavors. High magnesium water tends to produce more vibrant, nuanced cups.
- Calcium — contributes body and mouthfeel, but too much leads to scale buildup in your equipment and a heavier, sometimes bitter cup.
- Bicarbonate (alkalinity) — acts as a buffer. High alkalinity neutralizes acidity, which can flatten bright coffees like Shuksan or Hemisphere. Low alkalinity lets acidity shine through.
Hard Water vs. Soft Water
If you’re in a hard water area (high calcium and magnesium), your coffee may taste dull or bitter — and your kettle will scale up fast. If you’re in a soft water area (low minerals), your coffee may taste thin or sour, because there’s not enough mineral content to properly extract flavor.
Neither extreme is ideal. The goal is balance.
What This Means for Your Ritual
Different coffees respond differently to water chemistry:
- First Light coffees (Shuksan, Hemisphere) — bright, acidic, floral. They shine with slightly softer water that lets acidity express itself. High alkalinity will flatten them.
- Trailblazer coffees (Nooksack, Summit Ridge) — balanced and bold. More forgiving across water types, but magnesium-rich water will bring out complexity in the 6-bean blend.
- Cold & Wind coffees (Gunner’s Bowl, Baker Blue) — dark, earthy, syrupy. Slightly harder water can complement the body without adding bitterness.
What To Do About It
- Use filtered water — a basic Brita or pitcher filter removes chlorine and reduces some minerals. Better than straight tap for most people.
- Try bottled spring water — many specialty coffee enthusiasts swear by it. Look for a TDS between 100–200 ppm on the label.
- Avoid distilled or reverse osmosis water — stripped of all minerals, it produces flat, lifeless coffee and can actually damage some espresso machines.
- Test your tap — inexpensive TDS meters are available online for under $15. Worth knowing what you’re working with. We also recommend testing at least once a year — mineral levels and sediment can shift over time, especially in rural areas, and even city water can fluctuate with seasonal changes or municipal updates.
- Consider Third Wave Water — mineral packets designed specifically for coffee brewing. Add to distilled water for a precisely calibrated cup.
How We Do It
At home, we run double-filtered water — our LG refrigerator filter plus a whole-home filtration system. Every glass that goes into our kettle has been through two rounds of filtration before it ever touches the grounds. It’s a small step that makes a real difference in the cup.
On the trail, we always pack filtered water. Tap water at a trailhead or campsite is never a given, and when you're carrying a premium blend in your thermos, you want the water to carry the coffee — not compete with it.
Or head to Snowater Resort, nestled in the North Cascades, where the water flows straight from the Nooksack River — fed by glaciers high above. Something is fitting about brewing Nooksack blend with Nooksack water. Clean, cold, and mountain-pure. That's the kind of water that lets the flavor shine.
You can absolutely taste the difference.
The ritual deserves the right water. From the kitchen to the summit — start clean.
Go Deeper
- 📺 Watch: Coffee Water Explained
- 📖 The Coffee Roaster’s Companion — Scott Rao
- 🔗 Best Water for Coffee — Coffee Chronicler