Supported Bluetooth scales.

Two brew scales and one refractometer, named specifically. If your device is not on this list, it will not connect — and this page tells you that before you buy the app rather than after.

What connects today

The DiFluid R2 reads TDS into the Lab for extraction yield rather than weighing anything. It is listed here because it is the third piece of Bluetooth hardware the app talks to.

Acaia support is pending

This is the question most people arrive with, so it gets a straight answer rather than a footnote.

Acaia's communication protocol requires an official licence to implement. Coffee Aeye will not ship a reverse-engineered version of it — that route breaks on firmware updates, and it is not a defensible way to build against someone else's hardware. So the adapter is already written and sits behind a switch waiting on that licence. When it is granted, Acaia support turns on in an update, with no work left to do. Until then it is not in the shipping version.

What a connected scale actually adds

During a guided brew, a connected scale puts live weight and flow rate on screen against the current pour's target. You see the number climbing toward 60 g rather than glancing between a separate scale display and the phone, and the flow figure tells you whether you are pouring at a sane rate or flooding the bed.

That is the whole of it. It is a convenience during the pour, not a gate on anything:

• Without a scale — the brew-along runs on timings and target weights you hit on your own scale. This is how most people use it.
• With a scale — the same brew, with the weight and flow read for you as you pour.

Nothing else in the app changes. Bag scanning, recipe matching, grind conversion, the brew log, weekly stats, freshness tracking and the Lab are all independent of connected hardware.

Pairing

1. Turn the scale on and make sure it is not already connected to its own manufacturer app — most brew scales accept only one connection at a time.
2. Grant Coffee Aeye the Bluetooth and nearby-devices permission Android asks for on first scan.
3. Open a brew, tap the scale button, and pick your device from the scan results.
4. Tare on the scale or in the app; the two stay in step from there.

If the scan finds nothing, the cause is almost always the first point: the manufacturer's own app is holding the connection. Close it fully and rescan.

Why the list is short

Every scale here has a protocol that is either documented or stable enough to implement properly, and each one is tested against the real device. Adding a scale by guessing at its packet format produces something that appears to work and then silently reports wrong weights after a firmware update — which is worse than not supporting it, because you would not know to distrust it.

The same reasoning governs the grinder charts: 18 grinders with documented settings rather than a longer list padded with guesses.

Requesting a scale

If you own a Bluetooth brew scale that is not on this list, support@coffeeaeye.com — tell us the model. Devices with published protocols are straightforward to add; the rest depend on what the manufacturer is willing to document.