I’m a new Aillio roaster, I’ve roasted 10 times so far and absolutely loving the experience. What a beautiful machine.
My question is about the chaff collector(s). It looks like there are 2 places where chaff gets collected: in the black plastic chaff collector at the back, and in the metal chaff collector inside it. Some chaff falls out the front during roasting, but that doesn’t bother me.
All of my chaff is ending up in the black plastic collector, and literally no chaff is getting into the metal one. Is this a problem?
When I look more closely at the machine, the chaff comes in the top from the exhaust and drops down into the plastic chaff collector. I can’t imagine how the chaff should be getting into the metal collector.
Could someone please clarify for me where the chaff is supposed to be ending up?
I think you’re fine. I can’t explain why but I find some types of coffee seem to produce more chaff that get trapped by the mesh filter. I just did a Kenyan yesterday and there was almost nothing in the filter.
The screen cup is the filter which is used in a counter-intuitive way: the chaff collects on the outside of the filter. When you remove the filter from the rubber seal, that seal scrapes the chaff off the outside of the filter. After a roast you should be able to easily vacuum the collected chaff through the hole where the filter mounts or thru the little rubber door (flap? whatever it’s called) at the lowest end of the collector.
Chaff also dribbles out the front of the roaster below the door. It’s just a gravity exit… no air pushing it. There’s a tiny gap between the front plate and the outer housing of the roaster. The interior of the drum actually has a very slight low pressure (compared to the room) which draws air in the rear of the roaster thru the central part of the drum and then out thru the air duct at the upper right of the roaster and into the chaff collector. The air then passes thru the chaff filter and into the inlet of the exhaust fan where it then exits the roaster.
Thanks for the clarification KK, Cash and Bruce! Great to know where things were meant to end up – and using a vacuum to clear the chaff collector is a great idea! I appreciate your comments
The amount of chaff is dependant upon the beans and the process. Decafs have almost no chaff. Dry or natural process beans typically have the most chaff.
Chaff in the cooling bowl when you drop isn’t much of a concern for single batch roasts if you clean the chaff collector and screen after each roasting session. If you are doing back to back roasts, then it can make a difference.
The amount of chaff that will end up in the cooling tray is determined by several factors.
At higher Fan speeds, (the F value) more chaff will get moved to the chaff collector.
At higher drop temperatures there will be less chaff as it can burn off. BUT letting it burn off in the drum can lead to smoky flavors on the finished beans.
If the chaff collector screen gets clogged after a roast, then the heat in the drum will be different from the provious roast. The fan won’t be able to cool the drum the same as it did in the previous roast.
Hey Brian, I came here looking for a similar explanation. I “vacuumed” my chaff collector after my most recent roast and I swear there was next to nothing in it…now the cooling bowl was another story! I had to remove the hot beans/bowl just so I can vacuum the chaff clogging the fan so I can I cool it in time. Final fan speed was F4. Perhaps I’ll punch it up just before dropping, I just don’t want to suck out those last precious bits of momentum leading up to my finish. Have you played around more with this since?
I get virtually no chaff at the rear collecting area where the rubber dump plug is, the ratio from dump/cooling tray to the rear area is something like 80/20. It all staying in the beans.
I tried running higher fan earlier (F4 before yellow) on one of my last roasts but same issue. I’ll run it higher next time.
I also think I’ll try a roast without the collector cup and see what happens.
From my experience with my Bullet that Seems odd. Just to confirm-
are you roasting with the bean chute plug in place? If that’s left off or if the funnel is left in the bean chute, that will cause the exhaust fan to pull air from the bean chute instead of the drum.
there’s a small seal between the (sort of) rectangular transfer tube to the chaff collector- you should be able to see it when you remove the chaff collector. It serves to keep the exhaust fan from getting air from anywhere but the transfer tube (again- sort of; it’s not a perfect pressure seal). If that seal is missing or damaged the air flow from the drum will be affected.
Bruce
Edit- as a comparison I am getting enough chaff in the collector that I must vacuum the collector every other roast or the air flow will be affected to the point the Recipe-driven profile doesn’t track properly.
Which makes me think- have you run the Calibration on the exhaust fan? or for that matter confirmed the air flow exiting the rear of the Bullet? It would be pretty extreme but I wonder of there’s a exhaust fan motor issue… ??
I have the chute plug in place for most of the roast. I do gently lift a corner a bit to listen to 1C but the impact due to duration and amount of lift can’t be much.
I’ll check out the seal between the rear transfer tube and rear chaff collector.
I do vacuum the tube out between roasts (shop vac, bean chute plug off, hand briefly over rear transfer tube exit) to clear. There is usually not much in there or the rear chaff box but a ton in the cooling tray.
I’ve not calibrated the exhaust fan. Will read up on that.
I do lose a bit of chaff out the lower part of the front door during roasting but no beans. I think the door is shut pretty well but know it can leak sometimes. I did review SM’s noisy drum returned unit video. My drum is pretty hard to turn when off and makes a bit of noise but the spindle is only out the front by 1 mil+/-. I’ve not mic’d it.
I mentioned vacuuming the chaff collector to give you a sense of how much more chaff I’m seeing than the 20/80 ratio you mentioned. Just confirming for you that there seems to be a hardware problem. I only rarely see anything in the transfer tube, so if you’re finding something there to vacuum then exhaust air movement is probably lower than what I see.
You should see chaff dribbling out the front of the Bullet below the door- that’s an intentional part of the design. The fan located at the rear of the Bullet guarantees some air movement to carry that little bit of chaff out the front. It’s as it should be.
The drum shaft protrusion doesn’t sound in any way remarkable- probably just fine. The real criteria is the spacing between the front of the drum and the face plate. If you aren’t hearing any scraping and you aren’t getting beans trapped in front of the drum then it’s likely ok.
As a point of reference I roast at F2 till near the end of the roast when I up the fan to F3. I’m not using a huge amount of fan which of course would affect the movement of chaff. The only time the exhaust fan gets higher speeds is during the Cool mode when I’m shutting down.
Reviving an old topic, but I now own two bullets and my main one seems to collect chaff underneath the drum. I still get quite a bit falling out (that’s fine) but it seems to clog the air flow by the drum. Meanwhile this new to me bullet has next to no collection of chaff by the underlip of the drum. Any idea what could be causing this?
Thanks, i do experience the symptoms of the first link but the issues is more related to the chaff being stuck between the insulation and the drum at the door. I usually get a layer of chaff:
Just maybe, this could help. You will forgive me, but it’s difficult to know exactly what’s happening when you don’t see it. This is what comes to mind…
I feel you. My Bullet does not roast like it used to.
Between batches, I am vacuuming out chaff from the front. Though I don’t have a build up.
First thing to do when you have an airflow issue is to take about the chaff collector, and rebuild it completely. A loose bolt can cause airflow issues, which can redirect the heat, which can warp the plastic, which can cause another airflow gap, which can cause more issues… etc, infinity.
I’ve not had a batch I’m happy with in maybe a year. Drinkable, but not good. Always some major issue in the cup that brings it down.
I have found burnt chaff in the machine when I’ve cleaned it out, which accounts for some Smokey flavor issues perhaps.Which is also an indication some air is not moving.
