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!
This is a perfectly valid point of view, and for the first few months, I seriously doubted I could ever match a decent roaster. Now I can make exquisite coffee. Meh coffee too, don't get me wrong. But the more I learn, the more I can trust my instincts, the more I'm able to unlock some potential by tweaking temperature or time into 1C. Some beans still elude me (I had a Sidamo that smelled heavenly when green but that I could never roast properly), but it's, I think, true for most roasters except the very best. For me it's the ultimate step into complete coffee obsession. You need to truly know your beans to roast them properly. And then I can still play with grind size and temperature and pressure and time when pulling shots to make the best out of them.
Once the smoke is gone from the kitchen, the smell of freshly roasted coffee lingering in the house for the rest of the day... Man this is just heaven, makes you crave a nice cup instantly.