You’ve sourced the best beans, roasted them with precision, ground them fresh… but your coffee still tastes off?
It might not be your coffee—it might be your water.
Water makes up 98–99% of your cup, yet it’s often overlooked. In specialty coffee, water is not just a solvent—it’s a silent partner in your brew.
The Chemistry Behind the Brew
When hot water meets ground coffee, it extracts flavour compounds—acids, oils, sugars, and bitters. But not all water extracts equally.
Hard water (rich in calcium and magnesium) can under-extract coffee, muting acidity and clarity.
Soft or distilled water might over-extract, pulling too many bitter compounds.
What’s in Your Water?
Here’s a breakdown of key water components that affect flavour:
|
Compound |
Role in Brewing |
Ideal Range |
|---|---|---|
|
Calcium & Magnesium (Hardness) |
Aid extraction |
50–175 ppm |
|
Bicarbonate (Alkalinity) |
Buffers acidity |
40–75 ppm |
|
Sodium |
Adds perceived sweetness (in moderation) |
< 10 ppm |
|
Chlorine/Chloramine |
Off-flavors |
0 ppm |
|
Total Dissolved Solids (TDS) |
Overall mineral content |
75–250 ppm |
The Specialty Coffee Association (SCA) has water quality guidelines to help achieve a balanced brew.
SCA Ideal Water Specs:
- TDS: 150 ppm
- Hardness: 50–175 ppm
- Alkalinity: 40 ppm
- pH: ~7.0
How to Fix Your Water
1. Filter your tap water
Removes chlorine and some hardness. Brita helps, but might not be enough.
2. Use mineral packets
Add to distilled water for precision control. (e.g. Third Wave Water )
3. Test your water
Use simple TDS meters or water test kits. Know your baseline.