For many home roasters, the “first crack” and “second crack” are the most vital landmarks in any session. Recording the exact minute and second these events occur provides a baseline for understanding how a roast progressed. However, from a data-management perspective, capturing only these two points is like seeing the start and end of a journey without knowing the route taken.
Two separate roasting sessions can have identical crack timings and yet result in significantly different flavor profiles. This happens because the “path” between those landmarks—how quickly or slowly the heat was applied—often varies. To achieve true reproducibility, a roast log must capture the shape of the entire process, not just its milestones.
The core process fields
Regardless of the tools you use, every roast log should begin with a set of standardized process fields. These provide the essential framework for comparing one batch to the next.
| Field | Description |
|---|---|
| First Crack Time | The time elapsed from the start of the roast to the beginning of the first crack. |
| Second Crack Time | The time elapsed to the beginning of the second crack, if reached. |
| Total Roast Time | The total duration from the initial charge of beans to the final drop. |
| Drop Temperature | The recorded bean temperature (in ℃) at the moment the roast is ended. |
Capturing the “roast curve” manually
To record more than just these baseline landmarks, roasters often use a technique called temperature profiling. This involves recording a temperature reading at regular, fixed intervals throughout the session—typically every 30 seconds or every minute—using a notebook and a probe thermometer.
By jotting down these readings, you can build a simple “temperature-over-time” record by hand. This provides a visual representation of how the beans absorbed heat during each stage of the roast. For those who want deeper insight, these manual readings also allow for the calculation of the Rate of Rise (RoR).
What is Rate of Rise (RoR)?
RoR is a calculation of the number of degrees by which the temperature of the beans increases over a specific unit of time.
- How it is calculated: It is found by taking the difference between two adjacent temperature readings and dividing it by the time elapsed between them (e.g., if the temperature rises 5℃ over 30 seconds, the RoR is 5℃/30s).
- Why it is tracked as a curve: Roasters track RoR as a continuous curve on a graph to interpret the momentum of the heat inside the roasting machine. By observing this data, roasters can better understand what is happening during the roast and maintain consistency between different batches.
Streamlining the profile with Roast Book
At Kore Apps, we designed Roast Book to support this exact recording habit while removing the burden of manual math and manual plotting.
The Pro tier (available as a one-time purchase) includes an integrated Temperature Profile feature. Instead of drawing a graph by hand, users can manually add time and temperature data points directly into the app. Roast Book then automatically:
- Plots these points on a clear line chart (X-axis for elapsed time, Y-axis for temperature).
- Calculates the Rate of Rise (RoR) between every adjacent point.
- Visualizes the RoR as a dashed line on a secondary axis as soon as at least two points are entered.
This feature is built on the same underlying discipline as a paper-and-thermometer log, but it automates the visualization and math, allowing you to focus on the session itself.
App management and CTA
Maintaining a detailed process log is the most effective way to turn a “lucky” roast into a repeatable success. If you find that managing manual calculations and paper charts is becoming a barrier to your hobby, a dedicated digital tool can help sustain the habit.
Roast Book is available to help you organize your roasting journey.
- Free Tier: Manage up to 15 roast records, including a roast timer to capture crack points automatically and a tasting radar chart.
- Pro Tier: Unlock unlimited records, the Temperature Profile + RoR graph, bean lot management with automatic weight subtraction, and detailed statistical insights—all through a single one-time purchase.
Download Roast Book on the App Store: https://apps.apple.com/us/app/roast-book/id6763713928
Summary
A roast log that captures only the cracks tells only part of the story. By recording temperature readings at regular intervals and calculating the Rate of Rise, you gain the data necessary to interpret the heat momentum of your sessions. Whether you prefer the tactile nature of a manual notebook or the automated convenience of an app, capturing the “shape” of your roast is the key to mastering consistency in your home roasting.
For the bean data this process log connects to, see our guide: Beyond the Bag Label: Recording What You Actually Bought
For a broader look at how these records fit into a full recording system, see our hub article: Notebook, Spreadsheet, or App? Making Your Roasts Actually Repeatable
This article’s sources: Reconstructed by the editorial team from official sites, public information, and specialist media, from a recording and organizing perspective. Numeric, spec, and safety-related statements prioritize primary sources.
For roasting conditions and equipment operation, please refer to official information from your equipment manufacturer or bean supplier.
This article organizes information from a recording and organizing perspective. If you notice an error or outdated information, please contact us. Last verified: August 2026
