Setup Guide

1. Introduction

Coffee Hazel measures ΔH₂O — the change in steam — in real time during a roast, and detects the timing of first crack automatically.

The system is made of a sensor fitted inside the roaster's exhaust duct, a second sensor that measures the air in the room, the unit that joins them and collects the readings, and a desktop application.

First crack is what happens when heating raises the pressure inside the bean's cells until the cell walls break and steam is released. A characteristic sound comes with it.

Roasters have traditionally judged first crack by that sound. But it is affected by the quantity of beans, their number, their size and their moisture content, so the sound alone makes it hard to place first crack accurately.

This system reads the change in the amount of steam in the exhaust instead. By taking the difference against the steam in the room air, it looks only at the water coming out of the beans.

2. Copyright

Copyright in this system belongs to SORAMAME LAB INC.

Patent pending (application number JP 2026-177291).

3. In the box

• The COFFEE HAZEL unit
• Non-woven fabric bags (5)

4. What you need

• Wi-Fi (2.4GHz) or Bluetooth
  The 5GHz band is not supported.
• A roaster
  • with an exhaust duct or chimney
  • where the temperature inside the duct at the sensor position stays below 80°C
  • where the exhaust, even after being diluted by outside air, still carries enough steam to measure
  • where the exhaust flows out properly rather than stagnating
• A computer
  Windows 10 or 11, macOS (Intel or Apple silicon), or Ubuntu

5. What to prepare

• A USB Type-C cable
• A USB power source

6. The unit

1. Display button
2. Screw holes — for mounting the unit on a wall
3. Wi-Fi reset button — insert a thin wire, such as a straightened paperclip, to clear the Wi-Fi settings
4. USB Type-C connector — connect to a USB power source (cable not included)
5. Vent — the humidity of the room is measured through here. Do not block it
6. Room sensor — fitted on the back of the unit. Do not block the vent

7. Connecting to Wi-Fi

Have the SSID and password of your 2.4GHz Wi-Fi to hand before you start.

On first power-up, in a new Wi-Fi environment, or after pressing the Wi-Fi reset button, the COFFEE HAZEL display shows the following.

Open the Wi-Fi settings on your phone.

1. Choose the network named "Coffee_Hazel_Setup" and join it
2. "WiFi Manager" appears
3. Choose "Configure WiFi"
4. The 2.4GHz access points within reach are listed
5. Tap the Wi-Fi you want to use and enter its password
6. Tap "Save"
7. When the connection succeeds, the display on the unit changes

Once connected, the data screen shows the unit's IP address. You will need it to talk to the desktop application, so make a note of it.

Giving the unit a fixed IP address

Depending on your router, the unit's IP address may change when it is powered off and on, or when it reconnects. If it changes, you have to point the desktop application — and Artisan — at the new address each time. Fixing the address saves that trouble.

To set it:

1. Note the current IP address shown on the data screen (for example 192.168.0.183)
2. Press the Wi-Fi reset button to open the setup screen, and join "Coffee_Hazel_Setup" with your phone
3. Choose your Wi-Fi and enter the password
4. Type the address you want into "Static IP (leave blank for DHCP)"
5. Tap "Save"

The address you enter has to meet these conditions.

• It must be on the same network you are using now — the first three numbers the same, for example 192.168.0.xxx
• It must not clash with another device
• A number outside the range your router hands out automatically is safest. You can find that range in your router's settings

Many routers can also reserve a fixed address for a particular device — often called DHCP reservation or static assignment. If your router offers it, that is the more reliable way.

8. Connecting over Bluetooth

Where 2.4GHz Wi-Fi is not available, the unit can connect over Bluetooth.

If the Wi-Fi setup screen is left untouched for 60 seconds, the unit switches to Bluetooth mode by itself.

With the unit in Bluetooth mode, open the desktop application "Coffee Hazel" (V2.2.0 or later) on your computer and choose "Bluetooth" as the connection mode.

9. Fitting the exhaust sensor

The exhaust temperature where the sensor sits must not exceed 80°C. Measure it beforehand with a thermometer.

There is a lot of dust inside an exhaust duct, so wrap the sensor housing in non-woven fabric. A drawstring tea bag from a supermarket works well.

Replace the fabric regularly.

Roasters with a chimney-style exhaust duct

Fit the sensor inside the duct, then seal thoroughly with aluminium tape so that no exhaust escapes.

A joint in the duct downstream of the chaff collector (cyclone) is the best place.

Check that the temperature inside the duct is below 80°C.

Roasters without a chimney

Example: Aillio Bullet Roaster

Example: WE×SUJI portable mini roaster

Attach a PVC pipe to the exhaust and insert the sensor near the pipe's outlet.

TIP: Using a reducing socket at the intake draws in more of the exhaust, and a narrower PVC pipe at the measuring point raises the concentration of steam.

TIP: The same approach may work on other small roasters that have no exhaust duct.

Anything else

Please get in touch and we will advise.

10. Switching screens

Pressing the display button (1) cycles through the screens.

→

→

11. Installing the desktop app

The desktop application "Coffee Hazel" runs on macOS (Intel and Apple silicon), Windows 10 and 11, and Ubuntu.

Open the GitHub releases page from the button below and download the .dmg for macOS, HazelSetup.exe for Windows, or the .deb for Ubuntu.

Download the app App guide (Japanese)

Run the app on the same Wi-Fi network as the COFFEE HAZEL unit.

12. Updating the firmware

Firmware is updated over the internet, from the unit itself. No computer or cable is involved.

How to update

1. Check that the unit is on Wi-Fi — if the data screen shows an IP address, it is connected
2. Press and hold the display button (1)
3. "Checking for updates..." appears while it looks for a newer version
4. Then, depending on what it finds:
   • Already current: "Already up to date." appears with the version, and the previous screen returns
   • An update is available: "Update available!" appears with the current and the new version. Press the display button (1) again to start. If you do nothing, it cancels itself after 15 seconds
5. "Downloading..." appears with the progress as a percentage
6. "Update complete! Restarting..." appears and the unit restarts by itself. The update is done

If it will not update

The firmware version currently installed is shown on the logo screen at power-up.

13. How the system fits together

14. How first crack is decided

15. Warranty

The warranty runs for one year from the date of purchase.

Faults arising from use outside normal operation, deliberate damage, and damage from fire, disaster or accident are not covered.

Please register as a user when you buy.

User registration form

16. Contact

SORAMAME LAB INC
11-1 Sayama, Kawauchi, Kawasaki-machi, Shibata-gun, Miyagi 989-1503, Japan
(inside KURIYA COFFEE ROASTERS)
Telephone: +81 224-88-9019 (Japanese only)
Contact form

17. Radio certification