Eco-updgrading our roasters
When we moved from Kula to our new roastery in the old Paia Sugar Mill, we got a fresh start to think about our roasters. We knew we wanted to prioritize eco-friendliness and safety, despite those being complex ideals to accomplish.
Hold up: let’s take a quick step back and discuss how the vast majority of coffee roasters work. They have a gas source (natural gas or propane) that lights a fire under a rotating drum, heating the green coffee beans through conduction and convection (absorbtion of heat through the metal and air in the drum).
The byproducts of roasting are chaff from the coffee beans, plus various gases – including Volatile Organic Compounds (VOCs). To keep these potentially harmful gases from entering the atmosphere (and our lungs), many roasters need to use an afterburner – a secondary fire source which incinerates the chaff and VOCs at very high temps (up to 1250F).
Afterburners are incredibly resource (natural gas) and emissions intensive. However, without an afterburner, the chimney that exits a roaster looks, well, like a fire is burning – a lot of smoke and coffee smell in the air. Most roasters aren’t in rural areas, hence they need to use afterburners to clean their roaster’s air.
Our coffeee is roasted with equipment that emits 80% less CO2 and requires 80% less energy than industry standards.
Eco-converting an old roaster
At the time of the move to Paia, we only had our 40kg Italian Wampa roaster, which we’ve lovingly nicknamed “Tommy,” due to its Thomas the Tank appearance. Because of our prior rural location in Kula – where we operated for almost 20 years – Tommy did not use an afterburner. We had a very tall stack/chimney to ensure the neighborhood we operated in wasn’t bothered by the smoke. But we wanted to do better when we relaunched this company.
In our move to the Mill, we installed what one of our friends jokingly called “the water bong of roasters,” or VortX cyclone. It sits at the roaster’s exhaust and uses atomized water to shoot down the chaff and VOCs, cleaning the air and leaving us with compacted chaff for compost.
The end result at the terminus of Tommy’s stack is warm, clean air.
Our new roaster is eco-friendly by design
We realized at the end of ‘23 that we needed a roaster to compliment Tommy. We went looking for a lightly used Loring – known in the industry as being the gold standard for roasting the best coffee, as well as being the best for the environment. We found an S15 Falcon on the east coast of Canada and decided it was time for that roaster to have a tropical vacation (a story for another journal post).
Loring roasters are super efficient and use a single fire source to heat the roaster, while recirculating that same hot air to incinerate the chaff and VOCs.
The end result at the terminus of the Loring’s stack is extremely hot (1200F!), clean air. We don’t currently have any neighbors at the Paia Mill, but when we do, they won’t be complaining about our emissions!
In summary
We've eliminated the afterburner (resource intensive) need in both of our roasters:
One roaster we've installed a water cyclone that knocks down chaff and VOCs
One roaster recirculates hot air from the drum to incinerate chaff and VOCs
But wait, you mentioned safety at the top
Right. Safety. First. Dirty roasters get compacted chaff stuck to the walls of their exhaust ducting, causing fires. We have a thorough cleaning protocol AND we have extra “insurance” with our eco-friendly roasters.
The VortX cyclone, using water, keeps the exhaust ducting clean. And the Loring roaster – operating at such high temps – also keeps the pipes completely clean. Trust us, we’re the ones taking everything apart to inspect and clean it. Our mind’s have been blown by how clean everything stays.
Eco-friendly. Fire safe. Win-win.