CALC.H2O_007

Water
Calculator

Complete water toolkit: build DIY recipes, check if your water will corrode or scale your machine, and see if bottled water works for brewing.

H2O.RECIPE DIY Water

Quick Presets

Target Profile

ppm
Espresso: 50-100 | Filter: 35-85
ppm
Espresso: 40-70 | Filter: 35-60

Batch Volume

Hardness Source

Your Recipe

Magnesium Sulfate 0.00g
Sodium Bicarbonate 0.00g
GH: -- KH: -- TDS: --

Mineral Sources

Mg (Epsom): Brighter, fruitier extraction

Ca (Chloride): More body, heavier mouthfeel

Mix: Balanced profile

Instructions

Add minerals to distilled/RO water. Mix until dissolved. Use a 0.01g precision scale.

H2O.LSI Machine Safety

The Langelier Saturation Index (LSI) tells you if your water will cause scale buildup or corrosion in your espresso machine. Test your water to protect your investment.

Water Parameters

ppm
°C
ppm
ppm
LSI Value --
Corrosive
Balanced
Scale-forming
-2 -1 0 +1 +2
Enter your water parameters to check LSI.

LSI Interpretation

< -0.5 Corrosive

Will damage copper/brass. Add minerals or buffer.

-0.5 to +0.5 Balanced

Safe for machines. Ideal range.

> +0.5 Scale-forming

Will cause limescale. Reduce hardness or increase descaling.

Testing Tips

Use a TDS meter ($10-20) and pH strips/meter. API or Salifert aquarium kits work for GH/KH.

H2O.BOTTLE Analyze Water

Check if your favorite bottled water is suitable for coffee brewing. Enter the mineral content from the label.

From Bottle Label (mg/L)

Analysis

General Hardness (GH) -- ppm as CaCO₃
Alkalinity (KH) -- ppm as CaCO₃
Est. TDS -- ppm
Enter mineral content to analyze.

Good Brewing Water

GH 50-175 ppm
KH 40-75 ppm
TDS 75-250 ppm
Sodium <30 mg/L

Popular Waters

Crystal Geyser: Usually good

Volvic: Good for filter

Evian: High hardness - OK for espresso

Distilled: Too soft alone

Water Science

How minerals affect your coffee and your machine.

01

Extraction Power

Mg and Ca ions bond to flavor compounds, pulling them from grounds into your cup. Soft water under-extracts; hard water can over-extract.

02

Buffer Capacity

Bicarbonates neutralize acids. Too little = harsh, sour coffee. Too much = flat, chalky taste. KH around 40-50 ppm is the sweet spot.

03

Scale Formation

At high temps, calcium precipitates out as limescale. High GH + high pH + high temp = faster scale. LSI predicts this risk.

04

Corrosion Risk

Very soft, acidic water corrodes copper and brass components. Your grouphead, boiler, and valves are at risk. LSI < -0.5 = danger.