Handling the chaff collector on B2B roasts

I have an Ethiopia bean that produces enough chaff with 454 grams to require emptying the chaff collector after 1 batch. My question is what have others done when doing back-to-back roasts? My concern is, if I remove the chaff collector while the Bullet is pre-heating for the next batch, that the fan is not able to pull air through the drum. How do you handle chaff on back-to-back roasts?

I have a portable vac I use to vacuum the chaff collector thru the bottom plug/flap after each b-2-b batch. It’s during preheat and it causes a bobble in temps but it corrects quickly. I didn’t dream this up- this was a suggestion from Julio at Sweet Maria’s early this year (?) on a YouTube video.


Thanks Bruce, I’ll give that a try, as I was doing 3 b-2-b roasts at a time. This could get me through the session.
I did get an alarm half way through my second roast. It’s getting enough chaff off the wire basket while the fan is pulling at the same time. Ultimately, I would like to get a second complete chaff collector and do a quick swap of the whole unit.


Do you recall the alarm? was there an ErC (error code)? just an audible alarm with power resetting to 0?


I think it was just an warning A-08, I can’t recall if it was audible or what happen to the power. I simply pulled the chaff collector off and did a hasty dump of the chaff and was able to resume the roast.

I’ve only had A-08 one time. It got so hot the grip on the chaff filter weakened and the basket drooped down and stopped the fan. That was about the time SM pub’ed the video about vacuuming. I’m a believer in vacuuming mid-session!


Have you ever done a fan calibration? I’ve been working with Aillio support for the past week on an A-08 error. If you’ve already done a fan calibration you should see P - d and bL 26 when you enter the fan calibration screen. If not you may need to upgrade your firmware. I was running FW 540. Aillio recommended I update to FW 562 beta. I’m always nervous about installing anything that has the word beta associated with it. The SSD in my laptop died so the FW upgrade will have to wait.

I typically will just open the little door on the bottom of the chaff collector and tap out the chaff after each roast if it’s super chaff-crazy like some Ethiopian naturals. I’ll then remove the whole chaff collector unit every 3-4 roasts, quickly empty it & brush off the chaff basket, then put it all back on.

It does mess with the preheat a little but not a ton because the fan actually does not spin during preheat so you aren’t really messing too much with the airflow. You obviously are leaving the back of the air transfer tube open which isn’t ideal. But it’s worked pretty well for me. I did about 15 b-2-b like this with some pretty chaffy beans and it worked great.

Warning: the collector gets hot in places & the basket is extremely hot so be careful!


I received my Bullet in Sept this year. I came with FW 562 Beta pre-installed. I calibrated the fan within a week. After getting the warning, my routine for handling b-2-b roasts was to take the chaff collector off during pre-heat and shake out the chaff as quickly as I could. I am aware that this prevents the fan from drawing air through the drum, and do this task in about 20 seconds. Of course having an entire chaff collector, a hot swap could be done in much less time.
I’ve limited my b-2-b roasts to just the initial roast plus one more. I like to take the chaff basket out to brush off more chaff sticking to it after the two roasts.

I should have been more observant, on what the fan was doing (or not doing) during pre-heat. Looks like I could combine vacuuming and disconnecting the chaff unit as needed. Now I’m curious about the fan speed, I wonder if I could correlate a specific setting and how the RPM’s change at that setting during a roast. It might give me an indication as to how much chaff has accumulated on the basket.

Like others have responded, I open the little flap and vacuum it out, usually every two roasts. I have kept this up doing over 20 roasts back to back, and I’ve had no issues, even with chaff-heavy Ethiopian, Kenyan, or Guatemalan. I always make sure the little basket is clean before I start. By the time I’m done with the long roasting runs, it’s starting to get fairly clogged up, I’ve never seen it clog completely up.

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