The whole job
Pour it hot. Read it.
- 4‑65 °CSample temperature
- 0‑30%TDS range
- ±0.02%TDS repeatability
- 500Readings on board
Step one
Pour straight in.
The well is deep enough to pour into, so there is no pipette, and the magnetic lid closes over the sample for the reading. A shot goes through paper on the way in.
Step two
Press the button.
The same press at 8 °C as at 64 °C. Cooling Curve Compensation measures the sample and the room and calculates where the reading will settle, so the steps never change.
Step three
There is the number.
TDS to ±0.02% repeatability, with the sample temperature beside it, saved on the instrument. You need no phone to take the reading or to look it up later.
Temperature
From fridge to kettle.
Read cold brew straight out of the fridge and filter a minute after the kettle, on one instrument, with nothing to change between them.
One reading procedure anywhere from 4 °C to 65 °C, across 0 to 30% TDS, so filter and espresso use one instrument and one procedure.
Extraction, on board
The chart
Strength against extraction.
TDS and extraction are plotted together on the brew control chart. Swipe down to choose percolation, immersion or hybrid, and the target box moves to match the brewer you use.
Stacking
Average every repeat.
Read the same sample again and the screen shows the average with the spread beside it, so one stray sample never becomes your TDS.
Records
Every reading kept.
Five hundred readings stay on the instrument, each with its date, temperature and extraction: a production day of sign-offs, or a whole class's brews. Over Bluetooth, CoffeeOS links each one to the bean it was taken on.
A dial-in
See what your change did.
1.26%, then 1.29% a minute later. A gap that small comes from a grind step, not the instrument. When a cup tastes sour, the figure shows you whether to look at extraction or at the roast.
Zeroing
Choose your zero.
Zero once and every reading afterwards is measured from that point. Which water you zero against depends on where the figure is going.
Distilled water
The reference stays fixed, so a figure taken today and one taken in March are the same measurement. Use it when you send the figure to someone else.
Your brewing water
The reference is the water you brew with, so the reading shows only what the coffee added. Whatever your water already carries is subtracted when you zero.
Once a week is enough in most places. Zero more often where temperature and humidity swing.
Build
Bar, lab, roastery, van.
It lives next to a grinder. It gets splashed, knocked, and used with wet hands.
IP67Rinse the well under the tap, dry it with a cloth, carry on.
Magnetic sealing lidCloses the well for the reading, so nothing evaporates while the figure settles. It doubles as the dust cap.
13 hours of measuring16 hours on standby from a 3,000 mAh battery, charged over USB-C.
5–45 °C ambientRoastery floors run hot. Cupping labs run cold.
Deepened sample wellDeep enough to pour into without a steady hand.
500 readingsKept on the instrument until you sync them to CoffeeOS. A full shift, or a whole dial-in session.
Rebuilt heat dissipationThe tenth reading in a row is as trustworthy as the first.
CoffeeOS over BluetoothIn CoffeeOS, each reading is linked to the bean, roast and brew it came from.
Where it works
Your job gets shorter.
Whichever of these is yours, the cooling step comes out of it: the sample is read at the temperature it is, and the figure is on the screen before the next one is poured.
Cold brew and ready-to-drink
Batch 40 reads the same as batch 1, whether the sample comes warm out of the tank or cold out of the fridge. The figure is on the instrument before anything goes in the can.
Cafés
Check the batch brew before open and catch the morning it drifts. Extraction is calculated on the screen, so a spec check runs in the time it takes to pour the next one and nobody has to be taught an app.
Training
Hand a class a figure for the coffee they just brewed, inside the session. Six brews per student in ninety minutes, and the chart is on a screen the room can gather around.
Field service
Verify a super-automatic is delivering the strength it is programmed for, and put the figure in the service report. Eleven machines before lunch, whatever each one dispensed at, on thirteen hours of battery and an IP67 rating for a van.
Dialing in a new bag
A grind step, a different paper, another water. Each attempt is read the same way at the temperature it was brewed at, so the gap between two cups is the thing you changed and not how long each one sat on the counter.
For you
Alongside R2 Extract
What the second generation added.
R2 Extract is the instrument this one grew out of. These are the rows where the second generation does something the first cannot.
| Specification | R2 Extract | RS Extract |
|---|---|---|
| Sample temperature | 20–40 °C | 4–65 °C |
| Cooling step | Required for anything hot | None |
| Display | Monochrome | 3.5″ color touchscreen |
| Extraction yield | Phone required | On the instrument |
| Stored readings | Phone required | 500 on the instrument |
| Averaging a run | Phone required | On the instrument |
| Evaporation control | Open well | Magnetic sealing lid |
| Languages on the instrument | Numbers only | English, Chinese, Japanese, Korean |
| Battery | 430 mAh · 12 h | 3000 mAh · 13 h continuous, 16 h standby |
| Charge current | 5 V / 0.3 A | 5 V / 0.8 A |
| Ambient operating range | 5–40 °C | 5–45 °C |
Read anything from 4 °C to 65 °C, with extraction on the screen.