HazeLog - Coffee Roast Curves
Log, chart and repeat a roast
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Save the roast you got right, curve and all. Roast alongside it next time. No probe, one-time purchase, no ads, data stays on device.
HazeLog is a roast-curve logbook for people who roast coffee on a stovetop pan, hand-net, or small home roaster. Save the roast you got right, then run alongside that curve next time to recreate it.
No temperature probe required. Tap large buttons to log charge, temperature spots, first crack, second crack and drop, and HazeLog turns them into a time-vs-temperature roast curve automatically. No thermometer? Your event timeline and DTR still make a complete record.
■ The ghost curve
Mark a past roast as a target profile and HazeLog overlays it faintly on the live screen while you roast, showing the temperature gap and the time remaining to the next event (like first crack).
■ Features
- Live roast logging (large buttons, tap-to-undo)
- Roast curve with phase bands (drying / Maillard / development)
- Green bean master (origin, stock, auto-decremented per roast)
- Batch detail (automatic weight-loss %, roast level, tasting notes)
- Heat and damper operation log
- Automatic ROR / DTR analysis (Pro)
- Batch comparison view (Pro)
- CSV / PDF report export (Pro)
■ Quiet and yours alone
HazeLog works fully offline and stores everything on your device only. No account, no ads, no notifications, no tracking.
■ Pricing
Core logging, the curve and saving are free and unlimited. The ghost curve, analysis, comparison, export and unlimited beans beyond three unlock with a one-time Pro purchase (not a subscription).
HazeLog is a logging and visualization tool. It does not guarantee roast results.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, YANGLI CHEN, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- YANGLI CHEN
- Size
- 1.2 MB
- Category
- Food & Drink
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- ハゼログ Pro $5.99
- Copyright
- © 2026 CHEN YANGLI