# Water for brewing

Brewed coffee is about 98.5% water. If your coffee tastes flat everywhere, in every method, with every
bag, the water is the first thing to check — before the grinder and long before the coffee.

## Target

| Measure | Target | Why |
| --- | --- | --- |
| Total dissolved solids | 75–175 ppm | Below 50 ppm the cup reads hollow; above 250 ppm it reads dull |
| Total hardness | 50–100 ppm as CaCO₃ | Calcium and magnesium carry extraction |
| Alkalinity | 40–70 ppm as CaCO₃ | Buffers acidity; too high flattens everything |
| pH | 6.5–7.5 | |
| Chlorine | None | Ruins aroma at any detectable level |

## Practical answers

**Tap water that tastes fine** — use it, through a carbon filter to remove chlorine. Most municipal water
in the Pacific Northwest is soft and works well as-is.

**Hard water area** — a Brita-style pitcher filter removes some hardness and most chlorine. Good enough,
and it also slows limescale in your kettle.

**Distilled or reverse-osmosis water** — do not use it straight. There is nothing in it to extract with,
and the cup comes out hollow and flat. Add a mineral concentrate if you want to go this route.

**Bottled spring water** — check the label. Anything near 150 ppm TDS is a good default. Avoid mineral
waters above 300 ppm.

## Temperature

| Roast | Temperature |
| --- | --- |
| Light (Ardent Yirgacheffe) | 96 °C (205 °F) |
| Light-medium (First Light, Huila Reserve) | 95 °C (203 °F) |
| Medium (Lowlands, Nightshift Decaf) | 94 °C (201 °F) |
| Dark (Blackpine) | 93 °C (199 °F) |
| Espresso (Forte) | 93 °C (199 °F) |

Off-boil water is roughly 96 °C thirty seconds after the kettle clicks. If you own a
[Ridgeline kettle](../library/ridgeline-kettle-user-manual.md), just set the number.

Lighter roasts are denser and want hotter water. If a light roast tastes sour, the fix is usually hotter
water and a finer grind, in that order.

## Limescale

Hard water leaves scale in a kettle. Scale insulates the element, makes temperature control inaccurate,
and eventually kills the kettle.

**Limescale damage is not covered by the Ridgeline warranty.** Descale monthly in a hard-water area, every
three months otherwise. See [Descaling the Ridgeline kettle](descaling-the-ridgeline-kettle.md).

## Related

- [Descaling the Ridgeline kettle](descaling-the-ridgeline-kettle.md)
- [Pour-over brewing](brewing-pour-over.md)