Dark Liquid dripping from the back of the Bullet?

I noticed a couple spots of a darker liquid dripping from the back of my Bullet. I can’t imagine that’s expected, or a good thing. Any ideas?

Is the Bullet vented to the outside? If so, is it possible rain or mist has blown into the exhaust?

Pretty sure it’s coffee syrup. Moisture from the beans, condensing in the machine. Check the airflow.

This can happen when the metal chaff filter becomes clogged, or when the environment air is very high humidity. Makes a bit of a mess.

Thank you for the replies. The Bullet is not vented outside, just in the garage. I’m in California though, so definitely not especially humid.

I’ll double check to make sure nothing is clogged internally.

If not, is there anything to be concerned about due to the liquid?

it’s condensation. it’ll be from the impeller or exhaust dripping from the base of the chaff collector where the hot exhaust meets the colder metal (occasionally) it can also come from the front underneath the door. It’s a bit messy but not serious issue. Give the bullet a deep clean and you’ll be good to go…

Most likely cause your chaff filter is dirty. Soak it in Cafiza and boiling water for a few min.
FYI, over time you can damage the electronics if the humid air is not removed from the drum.


So, the filter was very dirty…pretty gross. There was actually some grey stuff on it as well as the chaff collector.

Is it possible this is mold, or ash?
It doesn’t smell moldy, which would have been my first guess.

How do you clean the inside of the chaff collector?

Take a look at the cleaning guide posted by Sweet Maria’s and follow it. When you clean regularly the roaster will perform more consistently.

Thank you! I shall.

I found that when the little rubber flap at the bottom of the fan chamber was not closed properly I would get the same drips. FWIW

I disassembled the chaff collector and went all out with Cafiza/Water mixture, a sponge, cloth and elbow grease! Was squeaky clean afterwards, like new.

Hope it helps, Cheers!

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Have struggled with this issue a lot. It’s a combination of residue collecting and when heated up it starts to drip, and, most importantly, air flow issue. Run the fan calibration and you should be good.

Thanks to everyone for your replies. I’m giving the machine a thorough cleaning today.

Any recommendations on how to clean this part? Does the fan section easily detach as well?

I use a 50/50 dilution of Simple Green spray fairly liberally and use a big wad of paper towel to wipe down.

The squirrel cage fan also needs to be clean - I let is soak in the same Simple Green solution. Others have used something stronger that is used for espresso machine cleaning but don’t let it sit in that stuff too long.

EDIT: for the squirrel cage fan I also scrub it with an angled grout scrubber (OXO brand works well for me)

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I find a weak solution backing soda to be an excellent solvent for coffee residue.

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If your bullet is left out in the cold, bean moisture from roasting will condense in the hopper. Take your bullet indoors when not roasting. Take it out and preheat it as soon as possible, this will reduce the condensation.