After spending so much time and energy with an entry-level home coffee roaster, here are my takeways

Can it make great coffee?

Absolutely! My preference gravitates towards light roasts or lighter medium roasts. Although the Gene is not very good at light roasts, lighter medium roasts are easily achievable. The coffee you can roast at home may never be as good as what the best artisan roasters can produce, but it will always be 1000x better than commodity supermarket charcoal you can buy everywhere (and cheaper too).

Is it a good machine?

Yes and no.

  • It’s easy to use because, apart from time, there is really just a single variable you can influence: maximum temperature. With a decent workflow you can produce excellent coffee, but it lacks everything people obsess about (temperature probes and Artisan integration, airflow control, power control, automation etc.) that makes a high-end home roaster much closer to a professional tool.
  • Ambient temperature (and I suspect humidity) influence it a lot, making batches hard to replicate. Target temperature and 1C can be as much as 1-1.5 minutes sooner in summer.
  • Airflow is everything, and chaff can easily block the chamber’s intake, stalling the internal temperature at 220-230°C and “ruining” (control over) a batch.
  • Batch size is kinda small at 250g, so if you wanna roast larger quantities, you must do several small batches in a row. I usually roast 4x250g batches in a single session, and it lasts me about a month.

Are complicated workflows necessary?

No. My personal workflow is much simpler and basically the same for every bean after preheating the machine at 220°C for about 10mins:

  • Dry at 180°C for 3 minutes
  • Increase temperature to 135-145°C depending on the bean, it should get there around the 7min mark. Hold until 1C.
  • Once 1C starts rolling (depending on the bean, around 8-11min mark), reduce temp to 220°C and dump after 1 minute (I built an external cooler that adapts to my vacuum cleaner, do not use the built-in cooling function, it sucks)

Is it worth it?

If your local roasters suck, all you can access is supermarket coffee or your local or online roasters are prohibitively expensive (don’t forget to still support great local businesses once in a while), if you’ve got time and love to experiment, if you love DIY, go for it!

  • WFHOPEnglish
    8•5 months ago

    So is your setup in your house? I understand there’s quite a bit of smoke and it can really smell your house out if you do it indoors.

    I live in an apartment so I don’t have much choice. There’s indeed a ton of smoke, however with the kitchen window open and the door closed, it’t rather contained.

    Do you let the coffee degas a bit before you brew with it? What’s your preferred brew method?

    Yes. 24h degas + 1-3 weeks aging. I almost exclusively brew espresso.

    You said you do 4x 250g batches per session. I assume that’s 250g of raw green beans going into the roaster… what’s the yield per batch coming out at the end?

    Yes. 250g of green beans yield about 215-220g of roasted coffee.

    How do you source your green beans?

    Online. I might be interested with alternatives in the EU.

    • @zigmus64
      2•5 months ago

      Your post and reply to my comment has sent me down a rabbit hole I’ve been down many times but with a new angle. I’ve wanted to try my hand at home roasting for a while, but now I think I want to try it on my grill outside.

        • @zigmus64
          1•5 months ago

          Well, it’s a practicality thing. I’ve researched all the various roasters out there over the years, and always balked at the price tag. I’ve recently been gifted a nice grill though and had the thought of possibly of using that. After some looking online I found that while not the most common way of doing it, some folks do it frequently.