A drum roaster sized for a household rather than a café, and built to do the job the way a commercial machine does it — beans tumbling against heated steel for ten or twelve minutes while you steer.
The drum is stainless steel, four inches by eight, and it takes 225 to 275 grams of green coffee with 250 grams as the sweet spot. That is roughly a nine-ounce batch, which works out to a week of coffee for most households and, more to the point, is a quantity you can afford to ruin twice while you are learning what you are doing.
The parts that decide whether you keep using it. Roasting produces smoke, and a great deal of it at the end of a dark roast, so this machine includes a built-in smoke reduction system — which is the single feature that determines whether a roaster lives in the kitchen or gets exiled to the garage by the rest of the household. Roasting also has to stop, sharply, because beans carry enough heat to keep roasting themselves after the drum: the external cooling tray and forced-air fan bring a batch down in four to five minutes, which is the difference between the roast you aimed at and the one that happened afterward. Chaff, the papery skin that comes off during roasting, collects in a deep tray that pulls straight out.
Control. The B runs under both automatic and manual control, so you can let it follow its own curve or take the heat and fan yourself mid-roast as the beans tell you to. That is the distinction from the P model, which stores nine eight-segment profiles for repeating a roast exactly; the B asks you to pay attention instead, and most people who stay in this hobby end up preferring that. The B+ variant adds a second thermocouple so that bean temperature and environment temperature read separately, along with slightly more capacity — worth knowing about if you think you will want data logging later. Manufacturer's warranty is one year.
What you will want alongside it. Green coffee, which keeps for a year or more unroasted and costs a fraction of roasted; a scale that reads to the gram for charge weight and weight loss; and somewhere to let the beans rest, because coffee off the drum is full of carbon dioxide and does not taste like itself until a day or two has passed.
One last thing, since this is a shop about economics. Böhm-Bawerk's claim in 1889 was that production taking the longer, more capital-intensive route yields more than the direct one, and he called that detour Produktionsumweg. Buying roasted coffee is the direct route. This is the other one.
