Chaff catcher / Bean blocker 9000XL

Don’t get too jealous.


I like it. did you leave out the ‘scotch brite’ filter? The chaff should pass right through the fan.

This was going to be my next project. I have the mesh bags already and ordered the flange adapter for the fan to make it easier to tie the bag to something.

And then I have a battery powered stirrer that does a great job and helps get the chaff out.

The Stirmate VS:

and the Stirmate wire stirrer which is much better than the stirrer paddles that it came with. It knocks loose the chaff and the fan pulls it out of the bowl.

It easily clips onto the bowl. I shortened the main shaft and added a split collar to keep the stirrer from falling out.


That’s pretty slick.

Where did you get the split collar? Or did you make it?


Thanks for sharing this!! Looks like a good solution that is cost effective. What did you use to shorten that shaft? I don’t have a lot of tools at home… :slight_smile:

Just a hacksaw and then used a file to debur the edges.

One of the nice things about this setup is that it doesn’t interfere with the dump chute.

Gnawing Season 5 GIF by The Office

Thanks @billc … Will put this on my bucket list

With the stirrer and the cooling fan working correctly (without the filter being blocked by chaff), I end up with no chaff in the bowl after cooling and no chaff in the finished product.

I have read a number of threads from people trying to eliminate chaff from the finish product.

Your solution to the cooling fan chaff collection is something I’ll consider sooner as I can stuff that sock into the semi-rigid I use to direct the exhaust closer to my hood vent. I just roasted a Brazil over the weekend it had a lot of chaff.

For the stirrer once you had shortened the shaft, how many of the U shaped thingy were you able to fit?

Just 2, but that is enough even for a 1000g roast.

Remember it is a work in progress. LOL

The nylon mesh bag is sold by Amazon as a fruit protection bag.

It is hard to see from the photo, but there is a 3d printed adapter mounted to the back of the fan. I took some aluminum wire and stuck it in the bag to hold it open.

The split collar allows me to set the depth of the stirrer wires so that they don’t rub on the floor of the bowl.

As I said: it is a work in progress…

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@krame and @billc - Curious, the mesh produce bag you’re both using, what material is that? I am seeing a lot of different material on Amazon including ones that are polyester+plastic! I would be a bit concern with the plastic/poly blend given that the air is a little hot when beans are dumped. I also see cotton and nylon ones. TIA.

They’re the plastic ones you’re thinking of. Dropped 900g of rolling second crack without issues.


I just now finished my first roast with the “New and Improved” (imagine trumpet flare sound effect here) Chaff Sock.

The ones that I bought are nylon and heat is not a problem.

The 10 X 14 are too big (and there are 50 of them) I took one and cut it to fit better and then used a stapler to sew it to the size that I wanted. (I don’t have a sewing machine but the stapler worked fine)

I rolled a piece of aluminum wire like a spring and inserted it to hold it open.
You can also see the 3d printed adapter that I bought from Etsy.

There is no chaff left in the cooling bowl tray (no vacuuming needed) Note that the white filter material was left out. The chaff is forced through the fan.

You could do a lot of roasts before having to empty the Chaff sock. The only down side is that there is a fair amount of dust that is created that gets through the mesh bag. I am in the garage, so that is not a problem for me, but in a kitchen setting, it might be messy.

Thanks @billc for the detailed video and photos. I may need to go with something with finer holes and see if it works better with the dust. The semi rigid vent hose I am going to insert this in may contain some of it but less would be better.

A nylon stocking might work. Cheap enough to try.

You could also try using a length of 4" dryer duct with a nylon legging on the end. The whole after fan construct doesn’t have to be just the bag.

I am using a semi rigid duct but I need that to direct the exhaust closer to my vent hood to vent outside. My setup Exhaust hood options - #41 by blacklabs

I wonder if a vacuum cleaner bag would work. Maybe needs more powerful airflow.