Infrared Bean Temperature Sensor: Introduction and Quick Guide

You are reading this because you are among the first in the world to roast with our Infrared Bean Temperature Sensor (IBTS). There are a few things you should know before you begin roasting.

You need to update your firmware before you roast for the first time, and you will need to continue to update it regularly.

Without getting overly technical, we can say that the old infrared sensor is there only to provide a reference temperature for the drum, but the new infrared sensor is pulling double-duty: it must read both drum and bean temperatures. In order to do this, it requires special firmware different from the firmware used by version 1 of the Bullet R1.

This technology is still brand new, and we will be updating the firmware regularly as we continue to improve it. Therefore, it is really important to keep your Bullet up-to-date.

To update the firmware, you must first install RoasTime 2 (RT2) on your Mac or PC. The installation files are available here: RoasTime 2. Please download the latest stable release for your operating system.

After installing the software, you can access the firmware update via the Tools menu in RT2 as seen below. You can choose either the latest stable release (recommended) or the latest beta, but make sure your firmware is up to date.

You can select either the stable release or the beta release

If your firmware update does not begin after 1 minute, do not turn off the roaster or disconnect the USB. Instead, quit RoasTime (you may have to End Task or Force Quit), reboot RoasTime, and try again. If you are on Windows, please select “Force Update Drivers” via the Tools menu before attempting to update the firmware a second time.

If the Firmware Update hangs, leave the roaster on and connected via USB, restart RoasTime and try again.

You will need to power your Bullet R1 on and off before its first use.

After you update the firmware and restart the Bullet, the new firmware will automatically detect that you have an IBTS, and then program it accordingly. Your control panel will display “rES”. After it has been programmed, you will need to disconnect the USB and unplug the Bullet R1 to completely power it off before the changes can take effect upon rebooting.

If after rebooting, the control panel still displays “rES”, then please repeat the process.

After roasting, you need to be extra careful to keep the fans on during the cooling process by waiting for the system to move from “Shut Down” mode to “Off”, as without a Germanium glass, the IR sensor is now unprotected from the heat.

Of course this is something we should always do, but it is particularly important for these new Bullets. While we’re talking about safety and maintenance, please take some time to read the manual. Although it has not been fully updated to include the information included in this QuickGuide, it nonetheless contains extremely valuable information that will keep your Bullet R1 happy and in-warranty.

One thing that will make you happy: Because the new IBTS does not require a Germanium glass to protect it from dirt and grime, you will no longer need to worry about wiping the glass clean. Still, when you take off the front plate for maintenance, be sure to give the sensor itself a wipe with a Q-Tip and alcohol.

Please be aware that the drum temperature readings during preheat will be different from those on the Bullet R1 v1.

As mentioned above, we have changed the firmware and altered the way the IR sensor reads temperatures, and that will inevitably affect your preheat settings. When attempting to duplicate the roast profiles or protocols of others, you should keep this in mind.

We hope to offer more concrete conversion values in the future, but for now we believe that a 300°C (572°F) with the new sensor approximates a 200°C (392°F) value from the old sensor. We also believe a value of 250°C (482°F) with the new sensor approximates a 180°C (356°F) value from the old sensor.

The IBTS is fundamentally different from traditional bean probes.

Traditional bean temperature probes come in different flavors, but they all suffer from the same limitation. Namely, because they are heated primarily through contact with the bean mass, their readings will vary according to the amount of beans in the drum, where exactly the probe is seated within the drum, and the thickness of the shielding around the probe. All of these things taken together make it impossible to translate readings from one roaster to another, or even from one roast to another on the same machine. They also make it difficult to know exactly what is happening in the roaster at any given time, as there will necessarily be a lag between the probe reading and the actual temperature of the beans.

Infrared sensors work differently. They measure the amount of light in a specific wavelength (known as infrared) being emitted by an object. This reading tells us how hot that object is. These readings are instantaneous and do not suffer from the limitations of traditional probes. In other words, there is no “thermometric lag” and different bean masses will still yield similar readings. No more guessing.

The IBTS curve looks different than traditional bean probes.

Because the technology is fundamentally different, the curve generated by the IBTS will also look different. Consider the 300g Roast Profile below. Please note that for the time being, in both Roast.World and RoasTime, the IBTS will 1be plotted as “Drum Temp” alongside the readings from the traditional bean probe, labeled “Bean Temp.”

300g — Traditional Bean Probe FC Temp: 165.9 / IBTS FC Temp: 204.3

The first thing experienced roasters will notice is that the “turning point” (the point when the traditional bean probe temperature begins to rise) has essentially vanished. The next thing you’ll notice is that the IR reading is much higher than the traditional bean probe reading, with first crack in the above roast occurring at 204.3°C on the IBTS (on Roast.World, this will still display as the “Drum Temp”) and 165.9°C on the traditional probe. Both of these differences are due to the lack of analog lag in the IBTS. In other words, you are seeing a real bean temperature profile curve for the first time.

Now take a look at the 1000g Roast Profile below.

1000g — Traditional Bean Probe FC Temp: 193.6 / IBTS FC Temp: 207

Both these profiles are using different charge weights of the same coffee. In this scenario, the first crack readings vary by almost 30° on the traditional probes, making it very difficult to match them together. But on the IR they are essentially the same, varying by only a few degrees. This is because bean mass does not influence the IR temperature reading in the same way. (Higher bean masses do slightly mitigate the “noise” generated from the IR picking up the vanes on the drum, but the difference is negligible, especially with our algorithm.)

Because these curves do feel quite different, it may be helpful for those with prior roasting experience to first roast as you normally would using the traditional bean probe and its RoR (Rate of Rise). You can then examine the IR graphs afterwards, in order to get a feel for what you should be aiming for.

We are all still learning and discovering.

For now, as in most things coffee-related, our reach exceeds our grasp. It will take more data, more analysis, and more time to fully reap the benefits of this new technology. Our firmware for the new IR sensor is still in beta for a reason: It’s going to get better.

For instance, we can promise you that in the future, we will be offering an infrared RoR reading to plot alongside the traditional bean probe RoR. (I know that I, personally, am eagerly anticipating that!) We will also continue to improve the mathematical algorithm we use to remove “noise” from the IR temperature readings.

Stay tuned for more updates coming soon.

Proud manufacturers of the Bullet R1 coffee roaster.

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