Bringing back the heating rate

Who can guess where this screen shot is taken from?

If you guess RoastLogger version 0.3 circa 2009, you’re right!

Notice there is a little field in there called “Heating Rate”. That thing made it into the earliest versions of RoastLogger, but I took it out since I never had the time to really calculate an accurate value. Around here, we will often not tackle a problem until we have a solution that we’re mostly happy with. It’s taken some time, but I’m happy to report that as of RoastLogger 2.2.3 which was released a couple of weeks ago, the heating rate (or, ROR [rate of rise] as some call it) is back in.

What we’ve learned since releasing this is that most roasters have already been using the heating rate, even before we had it on the display. How is that possible? Many roasters have been calculating this in their heads, taking mental snapshots periodically and calculating a degrees per minute rate in their heads.

Heating rate is a critical metric to watch, mostly after first crack when the roast temperatures rise at a much slower rate. In this phase, it’s crucial to not stall the roast by hitting a zero or negative slope. Now, with this number clearly visible, it’s much easier to see if you’re getting close to the danger zone. While the heating rate provides a very clear picture of what’s going on *right now*, there are still other metrics which are insanely useful, notably the environment/drum temperature.

As Shark from De La Paz Coffee pointed out in a guest blog post, the drum temperature give you a prediction of *what’s going to happen*. When you pump heat energy into any system, it takes some time for that system to react. With the environment temperature and the heating rate combined, you get the best of both worlds….a head’s up of what’s going to happen based on the heat entering the system, and an indication of the subtle changes when it matters most.

If you’re a RoastLog user and haven’t downloaded the latest RoastLogger, head over to our downloads section and download it now!