Initial Thoughts - US Roaster Corp 3kg, Shop Coffee Roaster
Seeing as how it’s so tough to find coffee roaster information, I wanted to mentioned a few things about the US Roaster Corp 3kg. Since it’s only been a couple of months of roasting on it, I’m sure I’ll have more findings down the road.
Knowing how to roast is one thing, but knowing the dynamics of various types of roasters and manufacturers can be something else. Since every roaster uses different materials, probes, sizes, thicknesses, heat/air dynamics, no two are a like.
It always takes a number of experimental roasts to make it do what you want. Much like a race car driver is an expert at maxing out track times, getting into a new car means doing a number of laps before understanding its behaviour, plenty of fine tuning, before hitting that ideal time again. Some input on the 3kg US Roaster:
Floorspace:
The roaster is very compact, compared to other guys like Joper. It’s narrow and tall, meaning it can save you some floor space. But you may actually need a stepping stool to load your green coffee if you’re under 5′10.
Drum:
Although most coffee roaster manufacturers boast heavier types of metal for the drum and construction, these models use heavy stainless steel. Some might write it off because of this, but it just means you need to think of your approach a little differently if you’re coming from the cast iron school. Although I’ve noticed there’s much less radiant heat, your conductive heat is much more responsive.
The unit does have an option for variable drum speed, which can be useful if you’re planning to run various batch sizes. Also if you’re into experimentation, variable drum also gives you the ability to mimic an air roaster approach.
Airflow:
Having a top blower air set up means you need to be careful on stripping away too much moisture from the bean. Comparing with the 3kg Joper, US Roasters airflow damper is stepless. On top of this, because the dampener is unable to be locked in place, it can sometimes move on you if you’re not on top of it. For instance, during a number of roast sessions I noticed that when setting it to Closed, it would actually open a touch, throwing off my setup.
Chaff Collection:
The unit comes with an internal chaff collection system, but definitely not nearly efficient compared to an external cyclone. Expect some chaff blow out from your exhaust without any secondary measure in place.
This isn’t meant to be a definitive guide, just observations for this specifics coffee roaster.
The spec sheet from US Roaster:
http://www.usroastercorp.com/files/3kiloroasterspecsheet.pdf