About Rate of Rise (RoR)
Table of Contents
Overview
This article introduces the Rate of Rise (RoR). It is a critical metric for logging and analyzing your roasting process in Cropster.
The RoR curve displays the current increase of the bean temperature over some time called the time expression (for example, 30 seconds or 60 seconds).
Understanding Rate of Rise (RoR)
The Rate of Rise (RoR) assists you in three different ways:
Roast speedometer (Acceleration)
The RoR curve measures the rate of change in bean temperature based on your Time expression settings. Mathematically, it is the derivative of the temperature curve. Think of it as your real-time navigation system, helping you maintain consistency and produce high-quality coffee.
Using a car analogy: if bean temperature is the car’s speed, then RoR is its acceleration.
- Positive RoR: The temperature is rising faster.
- Zero RoR: The temperature is constant (constant speed).
- Negative RoR: The temperature is dropping (slowing down).
A high RoR means the temperature is rising quickly. As RoR drops toward 0, the temperature curve flattens. A negative RoR means the temperature is actually falling—a "crash" you typically want to avoid.
Roast Track Preview
The RoR reacts to temperature changes much faster than the bean curve itself. By overlaying your current RoR with a reference, you can spot deviations 30–60 seconds before they appear on the bean temperature curve. This early warning gives you the critical time needed to make corrective adjustments.
Continuing the car analogy: if you expect obstacles, don't accelerate too fast, or you won't be able to slow down in time. Conversely, if you don't accelerate enough, you'll never reach your target speed (or bean temperature) on schedule.
Heat Development Navigation
The RoR highlights heat inconsistencies much more clearly than the bean curve. A "bumpy" RoR signals uneven heat development, which can negatively affect coffee aroma. Because these fluctuations are amplified in the RoR, you can spot and address them before they impact the final cup quality.
Rate of Rise (RoR) Settings
There are three different RoR settings:
- Recommended (the default setting)
- Sensitive
- Noise Smoothing
For all three settings, the RoR curve shows the temperature increase over a period; the Time expression setting allows you to adjust the size of this period.
For example, for the default Time expression of 60 seconds, the RoR shows the temperature increase or decrease over the last 60 seconds.
Changing the Time expression setting does not affect the shape of the Rate of Rise curve but only the unit of measurement (C˚/60s, C˚/30s, ...).
Recommended setting |
This setting offers the best balance between a smooth, interpretable RoR curve and a RoR that responds quickly to changes in the roast temperature. If you already use the RI5 Rate of Rise, nothing will change for you since the recommended setting is the equivalent to this setting with only slightly enhanced smoothing to even out very small spikes in the RoR curve. |
Noise Smoothing setting |
This setting can be used in case the RoR curve is hard to read due to probe noise when using the recommended settings. It is geared towards users who had difficulties switching to the RI5 Rate of Rise calculation method because of spiky RoR curves. It is strongly recommended to inspect the Temperature Probes to be able to use the recommended setting since the smoother Rate of Rise in this setting comes at the cost of a RoR curve, which is less responsive to changes in the bean temperature development. |
Sensitive setting |
This setting gives a very responsive RoR curve, but depending on the setup, the RoR can also be very shaky due to noise in the bean temperature measurements. |
FAQs
How can I adjust my RoR settings?
You can adjust your RoR calculation (settings) in Roasting Intelligence:
- Log in to Roasting Intelligence.
- Navigate to
Preferences > Roasting tab > Rate of Rise (RoR). - Select the setting.
- (Optional) Select the Time expression by clicking on the dropdown.
- Click Save to finalize the changes.
If you have further questions, feedback, or concerns, please submit a support ticket directly from support.cropster.com.