How to access the Rate of Rise graph on IKAWA Pro App
During the roast the ‘actual’ RoR is also mapped on the graph (in yellow). This allows you to see how the actual RoR is following the prescribed one, which is particularly useful to see if the roast ‘stalls’ after first crack, or how the roaster managed the beans going exothermic, then compensating quickly afterwards.
The IKAWA Pro Sample Roaster measures the temperature every second to the nearest 1/10th of a degree Centigrade, and you can see this level of precision on the Actual line of the Temperature graph during a roast. The readings for the Actual RoR are based on the temperature measurements at 15 second intervals. We have not applied any ‘smoothing’ algorithms, so the graph looks slightly angular, but is very useful for showing the trend.
If users want to delve even deeper into looking at Rate of Rise per second, you can do this by exporting the data for each second of the roast in CSV format and doing some analysis on excel. Our Roast Log feature means you can download unique roast data from all roasts you do on the 2.0 app.
WHY IS RATE OF RISE IMPORTANT?
The rate of rise is the speed that temperature increases (or decreases) during the roast at any given time – for further reading there’s a clear and articulate post about this by Morten Münchow on Coffee Minds. Conventional wisdom is that from just after the Turning Point, a good roast will have a steadily decreasing RoR.
The IKAWA roaster has the ability to heat up very quickly – much faster than conventional sample roasters, or large roasters too, and the small batch size means the Turning Point tends to happen within the first minute.
In our experience, people pay most attention to the end of the roast. At the time of the first crack, it’s particularly important to be aware of the RoR and use it to ensure roast profiles are getting the best from the coffee.
After first crack, the temperature itself should continue to rise slowly, but if that Rate of Rise increases after first crack it can make the coffee baked – even on light roasts. Matt Perger’s excellent Let’s Talk About Roasting post quotes Sang Ho from Square Mile by referring to it as the Flick of Death.
Similarly, it’s important that the roast doesn’t stall after first crack. This will happen if the rate of rise goes negative – i.e. temperature in the roast chamber decreases. This can lead to underdeveloped coffee and the qualities that go with that.
We’d love to know how this feature helps you to design and amend your profiles, and even translate them to larger roasters. Please drop us a line at [email protected].