A new roaster modification

For several months, we have been discussing and planning a roaster modification that was a little tricky to predict.  After a lot of discussions and then a few tests, we have moved into the production phase of testing.  The modification was a simple addition of a baffle to direct convection of hot air and thereby increase efficiency on the outside of the roasting drum.  Size, placement, and material were something we spent a lot for time on beforehand.  We currently have them installed on both roasters.

Initial results have been noticeable increases in aromas and clarity.  All roasts from the 21st on have this modification and you will notice a positive difference in your favorite coffees.  Special thanks to Luminarecoffee's Andrew Coates for help in the design and installation.

How to b-spec your coffee roaster

Take one coffee roaster. Replace every single wire and connectors. Sprinkle in some new components. Add a lot of sweat and frustrations... b-spec!

Before and After(control panel):



Before and After(Power Distribution):



Before and After(Chassis):

Tachometer for Huky300

Bicycle tachometer modified to fit and measure drum rotation rpm. This is done in anticipation of future motor replacement (of a higher rpm unit) and addition of variable speed control. Goal is to have drum rotation as part of the profiling, in additional to gas and air settings.

I replaced the stock 20vdc adaptor with a 24vdc unit, which "restores" the stock motor to it's default speed. The "as-purchased" configuration down-rated the motor (reason unknown). Drum rotation increased from 44rpm to 52rpm.

Trial runs already showed differences in the profile. At first glance, roasts seemed to be much more even at the higher drum speed. How it affect the cup will be determined in the coming weeks...

Minor (roaster) upgrade

What? You think I am going to leave my toys un-moded?! ;-)

After some discussions with Simon, it was felt that this is the best thing I can do right now to improve the consistency of my roasts. Onto the next level...

UPDATE (4/9/07):

Did a whole bunch of roasts this weekend. This mod has turn out to be a pivotal point of my roasting experiment. I now truly have control over the profile and roasts are so consistent that the curves are practically on top of each other. Getting the profile is also much easier than before. The fun begins....

- Ben C.

New Toy

Huky300 Coffee Roaster
Capacity: 100~360g (3.5~12.7oz), 250g (8.8oz) recommended (limited by cooling)
Size: 16" x 7.5" x 14" (L x W x H)
Weight: 13 lbs
Mirror Polished 304 Stainless Steel


Perforated Stainless Steel Drum with dual agitator vanes (4.7" diameter x ~0.1" thick)
50rpm-24VDC motor (running @ 20VDC -40rpm)


Custom machined stainless steel axial/bearing (vacuum heat treated)


Bean sampler and quick release gate
Solid rosewood handle
Dual temperature probe: type-K thermocouple and analog


Exhaust vent with gate valve and chaff collector


Accessories: Storage bucket, cooling basket, cooling/exhaust fan, DC power supply, bean funnel (hand made)


High-output Portable Butane Gas Stove with ceramic element (for infrared heat)


Just about every single piece on this roaster is hand made due to the limited production number. Everything is made to last at very high fit and finish (the thing is almost entirely of stainless). The craftsmanship is amazing.

I've done two roasts with it and it's not an easy roaster to use due to its all manual nature. I never use a direct flame drum roaster, let alone one that has air-flow control. The bean probe is very accurate and the thick gauge steel drum is able to retain heat once up to temperature. There are much to learn from this setup but I believe it will teach me more than any currently available home roasters (sample roaster does not count...).


- Ben C.