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!
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...
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....
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)
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...).