RoastPATH Forums

I am testing RP as a possible replacement for cropster. I understood the free subscription allows 10 profiles. However, it will not allow me to interact with any of my profiles accept one. I have 8 sitting there in my profile library but when I click one a popup says "invalid subscription" and redirects me to the billing page. It wont even allow me to delete any of the profiles because it wont let me in to even view them. What am I missing? Am I actually only allowed one profile?

I’m using a Mill City 500 roaster, and I’m having an issue with the RoR (Rate of Rise) line. Specifically, I’m noticing a difference at the “flank” phase and also at the “crash.” If anyone has insights or advice on how to manage or interpret these, I’d really appreciate it!

Do you guys have a specific bag sealer you would recommend. I would like a foot sealer. The options seem vast. Just wondering if any of you have one you like and would recommend. Or do you guys prefer a different style.

Mill City Roasters will be closed on Friday, January 23rd in solidarity with our community. We are proud to call this place home. (red heart) (snowflake)RoastPATH Portal Update V-20260120.1509 Release NotesMajor release highlights

• Greens Suppliers Expansion
• Greens Explorer Enhancements
• Forum participation open to free/hobby users
• Expanded Roaster Support

New Greens Suppliers

The forthcoming release of the web portal will continue the focus on greens that was started in the prior app release. Significant backend updates have been made to support new greens suppliers into our system. We now have the ability to support new suppliers large and small. Over the next few months we will be working to add new suppliers to the Greens Explorer. We have also laid the groundwork for these suppliers to automatically keep their greens inventory up-to-date in our system, or through periodic bulk uploads. We are working to expand the catalog of greens you can search when looking for your next green to add to your inventory.

Greens Explorer

As an ongoing effort, the Greens Explorer will continue to evolve to make searching for greens easier. Green details will now show any available public profiles for the selected green and give you a link to Path Intelligence for the green. Adding a starting profile to your Path Library will increase your confidence when purchasing a new green.

Forums

Free and Hobby users will now have full access to post and comment in the forums. Access has always been a balance between helping as many as possible and limiting the impact of non-professional, non-helpful, and abusive comments. If the forums stay a professional, friendly and helpful place, forum access will remain open to all uses.

New Roaster Support

Mill City Roasters will soon be shipping the newest generation of roasters from our factory in Minnesota. For RoastPATH, this required some exciting changes to the portal and the app. This portal update includes some changes needed to not only support the new Mill City Roasters but also expanded support for additional machines from other manufacturers. Watch for a future app update for more information on additional machine support.

Hello ,

I’m experiencing multiple issues after updating to the latest version of RoastPATH and would like to check if these are known bugs or configuration-related.

Issue 1 – Intermittent sensor dropouts:

After the recent update, the live sensor readings (BT, ET, and IT) intermittently drop out and show as “X”, then return after ~3–4 seconds. This keeps repeating during the roast.

Because of this delay, I can’t monitor bean temperature in real time, which makes active roasting very difficult.

Important observations:

- This issue only happens on the latest version.

- When I install and use an older RoastPATH version on the same machine, everything works perfectly (no dropouts, smooth real-time data).

- Hardware, USB connection, and roaster setup remain unchanged.

- Gas, airflow, and drum speed readings remain stable — only temperature sensors are affected.

- I am using a Mill City Roasters 2kg (2024) with a digital control panel.

Issue 2 – Modbus / USB warning:

I also receive a warning message stating that some readings are not being retrieved from the roaster and mentioning Modbus polling speed / communication issues (even though I am connected via USB, not Modbus).

Despite this warning, some values are received correctly, but temperature readings still drop intermittently.

This warning does not appear when using older RoastPATH versions with the same setup.

Issue 3 – Auto-roast / Replay:

Auto-roasting / replay functionality was working previously, but after the update I now receive a message saying that command sending is not supported for my roaster configuration.

What I’m hoping to clarify:

1. Is the intermittent BT/ET/IT sensor dropout a known issue in the latest release?

2. Is the Modbus/communication warning expected for USB connections, or could it be related to polling rate changes in the new version?

3. Are there any recommended settings (polling interval, USB configuration, compatibility mode)?

4. Has auto-roast / replay support changed in the latest update for Mill City roasters?

I’ve attached screenshots showing both the sensor dropouts and the communication warning.

Thank you in advance for your support.

Hey guys, I need some help with something that has been bugging me lately. We run an MCR 6kg with typical batch size of 10lbs. Since October-beg we have been roasting hard due to the season. But lately I noticed something rare... in short, I am seeing some abnormalities in the ET reading curve and the ET ROR curve that worsens as I roast more. - see images below. Some facts:

• The three images attached are a sequence of the same coffee, same batch, 3 consecutive days of roasting.
• I last cleaned the exhaust stack on Friday, Dec 12th (so fairly clean) and the exhaust fan on Sat Nov 28th.
• This issue does not happen on the first roast of the day. It is always smooth (I assume because the cooling fan is off)
• The spike on the ET curve happens as soon as I make adjustments to the exhaust fan (i.e. increasing from 15 to 18) and worsens when the cooling fan shuts off from the previous batch
• This issue started happening in October (after roasting about 1,000 lbs straight) and what I did then (from MCR advice) was to fully clean the exhaust stack and cap which I did and the issue basically went away
• I guess my issue now is that I am confused why if I just cleaned the exhaust stack last week, why is this issue reappearing so quick?
• Am I missing something? Is it related to the chaff collector?

Any help on this issue would be great

Update on 12.19.25

• Did a full evaluation of the condition of the exhaust vent cap using a cell phone and telescopic pole. Scary findings.
• Basically the top row of "window slots" of the vent cap was completely clogged despite believing that our cleaning process was actually doing the job
• One thing to clarify... our vent cap is 21ft above the roaster due to the design of the building and makes it very complicated to reach the cap from the outside.
• Our cleaning process didn't really account for the geometry of the vent cap vs the diameter of the exhaust pipe. Therefore in summary we were "cleaning" the vent cap but not really as our cleaning tool was not reaching the top row of slots on the cap.
• Following actions were taken:
• Inspection: Smartphone attached to telescopic pole to visualize interior and identify blocked slots.
• Cleaning: Drill-mounted spinner brush applied at low speed, increasing as needed; frequent visual checks to reach all slots; vacuum and wipe down debris.
• Verification: Post-cleaning roasts showed normalized ET and ROR behavior - perfect roasts
• Conclusion: We truly didn't follow MCR instructions to deep dive into the condition of the exhaust vent cap. We didn't understand the full geometry of the cap and the cleaning procedure was not doing the job.
• All roasts are back to normal after the deep cleaning of the cap and slots.

Hey there,

Curious if anyone else has attempted a 500g roast on the MCR-3D? My old 600g "sample" roaster is fidgety and unreliable, so I attempted to roast a 500g sample on my MCR-3D. After 3 attempts, I managed to get a somewhat normal roast curve. I increased my drum speed from 42 up to 60, initially lowered my fan speed, but ended up bringing it back up to around my usual setting, and lowered my charge temp to about 395 ET.

It was obviously a very fast roast. I hit G/Y a bit before 4:00, 1st Crack at 370, and dropped 8:30. If anyone else is interested, I will let you know how the cupping goes, but if anyone else has tried this and had good luck, please let me know. Would love to consistently use this for my samples. I made the profile public. Listed as 500g Sample on MCR-3D

Thanks,

Sean

I came in to roast today and while my computer is registering that the USB is connected, Roastpath is not recognizing it. So no temperatures or anything is registering. I was just roasting the other day with no issues and nothing has changed. I tried updating the app, restarting, etc.

Hi all,

I use an MCR-1, and my machine runs on propane gas with a regulator valve that I ordered from Mill City. The maximum pressure level is set at 3.5 kPa maximum, according to the factory recommendations. I'm currently roasting a blend from northern Peru with good density and different sized beans. My best roast times roasting a full batch are using an initial gas pressure of 3.5 kPa, low airflow at the beginning, gradually increasing it, and a 400 F° charge temperature. However, the maximum ROR peak is 12 C°. I'm wondering if even using the maximum gas level set by the factory is still insufficient to quickly transfer heat to the bean and obtain a faster recovery post-turning point? Would it be possible to increase the maximum gas pressure to 4 or 4.5 kPa to obtain a higher ROR?