Support instructions for using thermometers to log your coffee roast temperature profile. The article focuses ultimately on using an air coffee roaster, Popper is a Coffee Roaster, plus Phidgets and Artisan.
Knowing your coffee bean roast temperature is useful … but what’s the best way to monitor and log those temperatures? What are the pros and cons of complicated your roast process, and is it worth it? What do you need to buy and how do you set it up?
I made a 2 part video to provide some guidance, if this seems interesting to you. It’s not the first time we have discussed this by a long shot. We have a range of articles for air popcorn poppers, Popper Coffee Roaster, Stovetop non-contact thermometer, adding a dial face thermometer, etc.
Video: Recording Coffee Roast Temperature, Part 1 and 2
In Part 1 of the video I will discuss the value of logging roast temperatures, talk about the cheapest and simplest way to do this, and some important side notes if you decide to go ahead with it. (Key point on that… how you place the thermal probe, and where you place it, is so important it can totally invalidate any fancy computer-connected set-up you can dream up.)
In Part 2 I am going to focus on a simple computer roast temperature logging set up using Popper is a Coffee RoasterA machine for roasting coffee. Or the person operating it! The basic requirements for a coffee roaster are a heating element that gets suitably hot and a mechanism..., Phidgets (to connect thermal probes to the computer, total cost $66.50) and the free/donationware Artisan software to log the temperature graphs.
This is a basic introduction video to encourage people to explore the possibilities. The whole computer/roaster interface thing can get incredibly detailed and complicated, and that’s your thing, go for it. But it doesn’t have to be. Also, the Popper coffee roaster is really simple to hack with thermocouples (air popper roasters generally are). But something like the BehmorA popular electric drum roaster designed for home use, with variable batch sizes (from 1/4 pound to 1 pound) and a smoke-reduction system. It has been modified and... or Gene Cafe is not simple. To get a probe into the coffee mass of the drum is not easy at all.
Instructions: Popper + Phidgets + Artisan
Below are the basic instructions, shopping list, and set-up to get a Popper and Artisan connected using Phidgets modules, even if you are not a big techie. It’s new to me, and I was happy to see how easy it is. Hopefully you will be too. Please note that these add-ons are not things we sell, have any affiliation with, or have the knowledge to fully support. As for Popper, which we do sell, if you start poking holes in it, you are on your own too. It’s a risk. Consider that please.
1. Artisan / Phidgets Links and Materials Needed
Software needed (free/donation)
- Artisan software download via Github, Windows/Mac/Linux Etc (free/donation)
- Phidgets Control Panel download (see side bar for Windows, Mac etc)
Phidgets Hardware needed ($66.50 total)
- Thermocouple Phidget TMP1101 (currently $35)
- VINT Hub Phidget, currently $30
- VINT Cable 10cm length, currently $1.50
- Phidget site
Thermocouple Options ($4.50 – $9)
- SS Rigid Thermocouple 50mm
- or Quest SS Thermocouple 38 mm
- or Raw K-Type Thermocouple (oos right now)
Coffee Roaster Options ($29-$80)
- Popper is a Coffee Roaster (currently $79 or $89 with sampler)
- Poppo Hot Air Popper (currently $29.50, can be modified similar to Popper or other air popcorn machines)
2. Instructions for a Popper + Phidgets + Artisan Roaster
Note: This is outlined in the videos … please let me know of anything is uncleaar or needs a better image to help follow the instructions. -T
Thermal Probe (Thermocouple) Installation in Popper Coffee Roaster
For this set up we are using a lower Bean Probe that measures the bean temperature directly, and an upper Environmental Probe that measures the exiting air temperature. This is covered in the video Part 1 above starting around 5:50 . I am embedding the section of Part 1 starting at 5:50 here too:
I focus on drilling holes for the bare thermocouples, but in many ways the Rigid SS Types are better: SS Rigid Thermocouple 50mm or Quest SS Thermocouple 38 mm. There’s a separate video on how to add these to a Popper coffee roaster
Phidgets Connections and Test (see image gallery below too!)
- Connect the Bean Probe thermocouple ends to the first screw terminal inputs of the Phidget 4x Thermocouple module labeled 0. The red wire (positive) goes into the numbered screw 0 and the black wire (negative) to one of the inputs marked with an arrow to ⏚ (ground). Do the same for the upper Environmental Probe, using the slots labeled 1 on the Phidget Thermocouple module. (If you are adapting our thermocouples, you need to remove the yellow mini plugs to access the bare wires).
- Connect the Phidget 4x Thermocouple module to the Phidget VINT Hub module using the Phidget cable.
- Connect the VINT Hub to your computer with a USB cable.
- Open the Phidget Control Panel to check if it sees your Vint Hub and Thermocouple modules. If they are not seen, check the connections, and try unplugging/replugging in the USB connection. If it sees the modules but the test is RED in the Phidget Control Panel, you need to update the firmware. To do this simply double click on the name of the module and it should update in a jiffy!
- You will also need the Phidgets Driver: Windows / macOS / Linux You might need to grant access to Phidgets to connect via USB to external devices. On my Mac I had to ““Allow accessories to connect” in the Privacy & Security settings panel. Phidgets site states that the Mac version only has partial functionality vs Windows, but I was able to connect and upgrade easily.
Artisan Installation and First Use
- Download and install the latest Artisan version. Choose the correct installer according your operating system. You can run it from the virtual disk or install it onto your hard drive.
- In the Config Menu in Artisan, choose Machines, and scroll down to Phidgets. Choose Phidgets VINT TMP1101 2X TC. This is correct if you ordered the 4x Thermocouple module I linked to here.
- To test the Artisan setup for the TMP1101 module, just press the ON in the upper right corner of the Artisan screen. Check if the ET and BT readings on the right side of the window report the correct readings. If numbers do not pop up in a second or two, check the thermocouple wires as they are connected to the hub.
- Clicking the START button commences recording. (That doesn’t need to the the start of your roast. It just starts recording.)
- When you start the roast, either by adding the green coffee
Green coffee refers to the processed seed of the coffee tree fruit. Coffee is a flowering shrub that produces fruit. The seeds of the fruit are processed, roasted,... to the roaster, or turning on the roaster with green beans already in it, click the CHARGE button at the bottom of the Artisan screen. Charge refers to “charging” the roast drum with a batch of green coffee, in a bigger roaster. Artisan likes to use “pro” terms! - You should see your temperatures rapidly changing. Confirm your thermocouples are not moving around (or your readings will not be valid) and not touching hot metal.
- The additional buttons record “events” in the roast process. These are helpful but optional. You can control which of these buttons appear in the Events menu. DRY END is a term referrring to yellow or browning of the coffee. FC START is the beginning of First CrackFirst crack in one of two distinct heat-induced pyrolytic reactions in coffee. It is distinguished by a cracking or popping sound in the coffee, and occurs between 390.... FC END is obvious, as is SC Start – Second CrackAfter First Crack, a roast reaction around 440 to 450 degrees that is distinguished by a snapping sound. Second Crack is the second audible clue the roaster-operator receives.... DROP is another term from the trade referring to when the roast ends, when the coffee drops out of the roast drum into the cooling tray. You can STOP recording after the end of the roast, if you don’t want to record the cooling cycle. You can SAVE your recorded roast, to recall it or to use the COMPARATOR (under Analyse menu) to check 2 roasts against each other … kinda interesting!
- If you forgot to Save, when you click the RESET button it will ask you if you want to save your roast file.
- There are many other settings, tools and configuration adjustments available in Artisan. If you use Artisan a lot and like it, take time to donate! Artisan Plus is a new paid version for inventory tracking, mainly for small shops etc. I don’t know much about it.
- The Artisan site has great pages detailing all of the technical details of setup, settings and menus!
Additional Links
- Phidgets is based in and ships from Canada … and produce many other neat interface modules. I am exploring an option with servos to automate roaster adjustments, more precise than turning by hand! We have no affiliation.
- Artisan is a freely distributed software package that has some commercial options like Artisan Plus. We are not affiliated …but support the project and community. We encourage you to donate if you find the software useful! Artisan Phidget Set Link and instructions (some product links outdated)
Keeping in SIMPLE: Temperature Logging Methods / Materials:
- Low Cost Celsius Thermometer at SM ($5.40)
- ThermoPro dual probe thermometer ($20)
- Adding a thermocouple to Popper is a Coffee Roaster (video)
- Adding a thermocouple to an Air Popcorn Popper (video)
This video, from the Popper is a Coffee Roaster site (hence ads, sorry, not a business account) details how to drill a popper differently for the threads of the SS Rigid Thermocouple. So it is a little different than the raw thermocouples detailed in the videos above. Note that I am referring to a different measurement, and starting point in this video, to find the right drill point.
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11 Responses
Thanks for the videos! I’ve had this exact setup for around 8 months now, and love it. I poke my ET probe through one of the holes in the front chaff collection piece. I find that it’s a great tool to help replicate (or intentionally deviate from) roasts on the not-so-concise popper. As you alluded to, Artisan has the ability to pull in a previous roast profile in the background so that you have a reference point as your subsequent roasts progress.
One thing that would be great if this catches on would be for people to share their roast profiles much like the Aillio RoastWorld site. Maybe that’s already a thing in the Artisan community. Popper roasts are going to be unique, though…
There’s no way to attach files here, correct? – images or artisan .alog files??
Thanks for the note. Honestly I only have about 15 roasts on Popper with artisan, so just starting to build my understanding of how to truly use it. Installing the exit air probe in the top lid / chaff basket sounds like a good idea. What I find most useful so far is using the read out from my wattmeter that’s quantifying the heat setting on the popper, and relating that to the roast temperature I’m recording. I wish there was an easy way to record that change in heat, setting or fan speed as an event in artisan. Have you found a method? And yes, it’d be interesting to share roast curves. I know we can upload files to this WordPress media library, and then create a link to them, but I think having everybody able to send attachments to comments isn’t possible. I bet we can find a workaround though.
Brilliant!
Oh, you can do this to a Behmor too? I cannot tell you how much it would improve my guesswork.
1) The behmor display is almost unreadable in daylight…(I roast in my Garage during the day with the door open.)
2) I have to push B…decide if I am going to change the heat to 5, or 4, or oopsie 3 … sometimes late, because I can’t watch a continuous charted graph of my temperature.
3) B temperature isn’t really measuring what the bean is experiencing. It is off to the case somewhere and is influenced (perhaps inducing error) by the afterburner activation.
Please add a series on how best to mod the Behmor for this gadget. THANK YOU!!!
Hey Charlie, thanks for the note. You can add a probe to the Behmor, but the tricky part is putting it somewhere out of the way. I wrote a piece that covers this in some detail that you can see here, but it was not in an ideal spot. It was out of the way, but very close to the elements and the temps were super high. The point of the post was to see if the older 1600 model ran hotter than the current 2000 series, which some people believed, so I wasn’t as concerned with finding a spot in the chamber that would clock readings in line with “normal” BT temps. (In case you’re wondering, the new model runs just as hot as the old one, despite what the thermistor LED readings would have you believe!). To do a proper BT reading takes quite a bit of modification, drilling side panels, drum, etc, and not something we are comfortable advising people to do. I personally don’t think the payoff is all that great, either. But if you do want to go that route, I know for a fact there are posts about doing that modification online.
Thanks again for your comment, and glad you enjoyed Tom’s video!
-Dan
Could this be used on a Gene Cafe hot air roaster?
I would appreciate any information if it could….
Warm Regards
B Swanson
It would be feasible to use probes in mounted in the initial heat flow before it enters the roast chamber or in the exiting air flow. But getting a probe into the drum, to probe the beans as they roast, is the issue. That’s hard. Still it could be useful to set it up even if you are not probing the beans.
>>> I wish there was an easy way to record that change in heat, setting or fan speed as an event in artisan. Have you found a method?
I agree, that would be great. I use a spreadsheet at the moment much like the paper notebook that you showed. I see where other Artisan users do set up automation with sensors and servos etc., add buttons add to record other events. Artisan is so flexible, and works with many external devices, I’m sure a lot more is possible. On the popper I tend to stick to Fan=high 99% of the time, and then vary ‘Heat’ based on what my Watts Up meter says – similar to your other popper videos with a Watt meter. My 2 wattage stops tend to be 880-890w and 1020w +-10-20w depending on the power delivery state at that day/time. That’s the granularity of the ‘step’ that the smallest possible nudge on my popper’s heat dial gives, which is fine.
Something else I noticed in your video – your FC BT seemed a bit higher (415F IIRC?) than what I usually see. Maybe it’s a mix of that particular bean and where the probe placement lands vertically in the roast chamber. My FC BT reading tends to be closer to 395-405-ish, BT probe is 5-3/4″ down from the top.
I usually make that nudge from 890 to 1020w at 5 or so degrees F before anticipated FC according to the BT probe, to give it that push through FC as moisture is expelled and wants to drop the temp – if that’s even a consideration at this small scale. Fun stuff!
Thanks for the added details. Your experience with this is great to hear about… I do notice how much the temperature readings can vary and I think it’s type of probe and probe placement. Your readings are spot on with what is expected from other machines. 415 is way high. This is a concern when people are using all same equipment, and same method, but get different results. So I want to be sure to say that from machine to machine it’s not Going to line up exactly. I have added probes and run artisan on 3 poppers and each was different in terms of recorded temperature of 1st crack start.
I didn’t notice the wattage level you were at during the test roast or did I mess that.
Thanks, I very much enjoyed the videos.
Hi Frank, I believe this roast is also covered in this adjacent post where we list out the watt settings. In this case, it’s 960 watts for the first 5:55, then 1115 watts for about 1:05. Hope that helps!
Best,
Dan
Thanks Dan, I guess that I missed that.
Frank