Recipes & Measurements
Log every recipe and measurement with total precision. Save your coffee details, brewing ratios, and add custom notes for each extraction.
Brewmetric
Extraction science
in your pocket.
The professional TDS and coffee extraction calculator for iPhone.
01 / Scientific precision
Official SCA formulas.
Percolation and immersion formulas for precise coffee calculations, every single time.
02 / Native & offline
Built for iPhone.
Recipes and measurements stored securely on your device. Ready to use without an internet connection.
03 / Universal & subscription-free
Any refractometer.
One upfront payment unlocks the entire app forever. No proprietary hardware. No subscriptions.
01 / Plan
Design your recipe
before brewing.
Calculate all parameters of your recipe before touching the coffee. Enter your extraction targets (Extraction Yield and TDS) along with your brew water, and Brewmetric automatically calculates the dose, beverage weight, ratio, and dissolved mass.
02 / Measure
Analyze your
actual extraction.
After brewing your coffee, enter the data from your refractometer and Brewmetric calculates your Extraction, the true amount of dissolved mass, and provides a complete diagnosis.
Over-extracted.
Under-extracted.
Or right in the ideal zone.
03 / Interactive Extraction Chart
Understand
your cup.
A professional tool inspired by the SCA Brewing Control Chart that visually shows where your coffee falls. Customizable ideal zones, ratio lines, and dual data points let you instantly compare your actual cup against your plan.
- Ideal zones
- Define your target.
- Ratio lines
- See the relationship.
- Two data points
- Compare plan and cup.
04 / The complete toolkit
Everything
you need.
Smart Diagnosis
13 exclusive classifications with visual indicators and actionable advice to help you instantly fix and improve your extractions.
Export Anywhere
Export your recipes and measurements in multiple formats: beautifully designed PDFs, CSV spreadsheets, or JSON for developers.
Three Brewing Methods
Built-in support for Espresso, Filter Drip, and Immersion, applying the exact scientific formulas required for each method.
Advanced Settings
Pro-level controls for every extraction variable: adjust moisture, CO₂ content, brewing temperature, LRR, and even define custom ideal zones.
iCloud Sync
Your recipes and measurements sync automatically across all your Apple devices via CloudKit.
05 / Compare
Brewmetric vs
The other app.
| Feature | Brewmetric | The other app |
|---|---|---|
| Price | $9.99 | $39.99 |
| Compatibility | Any refractometer | Proprietary hardware only |
| Interface | Modern (SwiftUI, 2026) | Legacy (since 2010) |
| Formulas | The same (Lockhart 1957, SCA) | The same |
| Updates | Regular updates & new features | Abandoned years ago |
06 / Yours, for good
$9.99
One-time purchase.
No subscriptions.
No in-app purchases.
Includes all future updates.
App Store Pricing
This is how pricing works on the App Store: we set a price in US Dollars, and then Apple automatically defines the price in your currency. We don't set the price in each country.
Please check your App Store to find out how much Brewmetric costs in your country.
07 / The science behind the cup
Why measure
extraction?
You already know when your coffee tastes good. But do you know why — and how to repeat it every single time?
< 18%
Under-extracted
Sour, thin
18% – 22%
Ideal
Balanced, sweet
> 22%
Over-extracted
Bitter, harsh
The science is simple. Coffee is a fruit, and we extract it to reveal its natural sweetness. Hot water dissolves compounds from ground coffee at different rates. Too little extraction and it tastes sour and thin. Too much, and it's bitter and harsh. The sweet spot for Extraction Yield sits between 18% and 22%, whether you brew espresso or filter.
The problem is, you can't measure this by taste. You need a coffee refractometer — a small optical instrument that reads your coffee's concentration in seconds. Then you need Brewmetric to turn that number into actionable data: extraction yield, strength, ratio, and a clear diagnosis of what to adjust.
Measure TDS
Place a drop on the lens
Calculate extraction
Enter reading in Brewmetric
Dial in your recipe
Hit the 18–22% sweet spot
Any refractometer works.
From the DiFluid R2 Extract (~$199) to the VST LAB Coffee III (~$700). Brewmetric is universal.
Brew better
with data.