Heat gun/flower pot coffee roasting

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
DanN
Posts: 89
Joined: 10 years ago

#1: Post by DanN »

Hello all,

I am a new bee to coffee roasting and I started coffee with pop corn popper and used Heat gun/ Flour sifter for a while. Though the taste was good, the sifter did not have any heat retention properties and I had to compensate by using High heat/high air from the start to push the roast and did not care too much for the flavor. So I tried my hand on stove top roasting with cast iron pot. More scorched beans and metallic taste.( maybe the cast iron pot was new and yet to be seasoned )

So I started using a Unglazed Terracota flower pot after seeing videos of folks in Latin america and also some in Japan using clay as a roasting medium for superior heat retention properties. So started stovetop roasting with flower pot and a whisk I got at Lowes. Now I tasted coffee with more body and though good, I wish it was a bit faster as using more stove top heat only resulted in charred beans.

I read somewhere that a setup which uses the least amount of heat and that gets you a faster roast at the same time was the ultimate setup. So I am also using my heat gun at the "lowest/medium heat" setting to get a faster roast, at the least heat setting to emulate a Heat gun / dog bowl setup.

So I preheat my clay pot to 250F-350F(depending on the bean) on stovetop( medium heat) and then use my heat gun at the lowest setting. This gets me to first crack in about 6-7 mts. By using the clay pot ( conductive heat alone) it took 11-13 minutes. By using the heat gun setting alone on very HIGH it took 6 mts . This setup gives me the best of both worlds where I can use the least amount of heat possible and yet roast fast and I roast 150grms - 227 grms at a time.

Now that I have both conductive and convective heats on demand, looks like I can fine tune my roast profiles at any direction, though the setup might be very primitive. After having watched Joe Maracco's roasting videos last week on costa riccan geisha's( hosted by Dave Borton ...Thanks Dave) , I use only stove top heat for 3-4 mts to penetrate the bean core with conductive heat and then after yellow, I reduce stove top heat and start using heat gun heat for more convective airflow. I roasted many small batches ( 150 grms - 227 grams) and the setup is very very responsive. Also impressive is that the beans are all uniform , though the setup is very old school and all I use is a balloon whisk.

I just wanted to seek your suggestions. Am I on the right track or should I start using heat gun ( convective heat ) right from the start ? . Also in some probat sample roasters setup guide (which I read online) I read the instruction was to keep heat fixed and control roast by controlling air flow. Can I do that here in my setup by using heat gun heat as means to modulate airflow. My heat gun Wagner ht3500 has 12 settings ..6 on low air and another 6 on high air, and I tend to always use the low air setting for better flavor. At the end of the day is all heat the same , regardless of its conductive or convective and how does it affect heat transfer to the beans. For now I tend to use heat gun heat after yellow and stick to pure conduction during the early stages of the roast.





Appreciate your suggestion Guys !

DanoM
Posts: 1375
Joined: 11 years ago

#2: Post by DanoM »

Well, I don't know anything that will help you, but I like your flour sifter video!

The flower pot could make a good heat retaining container for the sifter if you rig up a hole for the "beater bar".

Also if you put a hole/port in the bottom or side to fit the heatgun you might have a better heat control mechanism. Choking off airflow on the top could be done with a terra cotta pot base or even a pot lid possibly. If you need more clearance another pot inverted over the top might work too, but you can't see the beans then.

Keep us updated!
LMWDP #445