I have been home roasting with a Gene Cafe since early this last summer. I chose the Gene Cafe specifically because it appeared to be designed for attachment to a permanent vent solution. However, I've since found that the three inch exhaust is a very rough fit and that the chaff collector leaks smoke as well. The vent hole I have installed in my house is also less than optimal since it tends to leak cold air in quite a bit even with two stops installed. Does anyone have a setup in place that has very little (or better yet, no) smoke leakage when roasting? What are the elements you have involved to create your smoke free roasting apparatus?

  • This question seems to be more about mechanics than coffee.
    – Ataxia
    Commented Jan 29, 2015 at 22:46
  • Correct. It is about the mechanics of roasting coffee. Commented Jan 29, 2015 at 22:49
  • See also this question about home roasting from Seasoned Advice. The accepted answer basically concludes "do it outside." Other answers to the question include impressive displays of ingenuity! Worth a read.
    – hoc_age
    Commented Feb 12, 2015 at 15:47
  • It's below freezing 7 months out of the year here. Another two months or so it's still just above freezing. That would leave far less than half the year I could roast outside, so it's not an acceptable answer in this case. Commented Feb 12, 2015 at 17:13
  • 1
    @AndrewMattson I roast with a popcorn popper outside. No, not when it's -30C - I'll wait till it warms up a little. Below freezing is fine and is not -20F. Commented Sep 7, 2016 at 20:17

2 Answers 2


I finally noticed that the chaff collection unit is actually several pieces that don't fit as well as they could. I took it apart and sealed the seams with high temperature engine gasket sealant. I then used the sealant to connect the vent hose to the top of the chaff collector (also a very rough fit).

I still have some problems with cold air inflow on the vent through the house wall, but I can disconnect the vent hose from the house vent and stuff it with rags or other temporary insulation material if I choose.

All said and done the machine is leaking far less than half the smoke it was previously. It seems the chaff collector was a main part of the problem. This makes sense as the exhaust there is making a 90 degree turn, expanding into a chamber, then compressing back into another pathway.

UPDATE: enter image description here

Complete misunderstanding of the problem. The exhaust vent is sized down and WILL connect and properly seal on a piece of exhaust pipe fitting. I am not sure why the company sized it this way, but sealing the seams and using a piece of exhaust joint (rather than slipping the vent hose/pipe over the exhaust) works like it was probably designed to.


I'm roasting with the Whirley-Pop so I doubt this will be too helpful to Chris, but I'll add my answer for the sake of completeness. The first time ever I roasted, I was waiting for a "second crack" that must have already happened, and before long my apartment looked like a scene from Backdraft. I learned my lesson and roasted outside on a hot plate, but after a while I decided to try it indoors again.

I just have a basic fan under a microwave, but I'm now at the point where if I roast 1/2 cup at a medium heat, and ensure that I pour the hot beans out while still under the fan (no taking it to the sink!) my apartment comes out relatively unscathed.

I've been trying to figure out why more people don't roast at home, and I have my suspicions that the oil and tar-laced fumes have almost everything to do with it. I'm curious to hear other ideas on the matter.

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