Seasoning the Drum
Lots of calls lately from folks who have never roasted or folks stepping up from homeroasting rigs. Let’s see if we can help with a blog on seasoning your roaster drum and get you roasting!
First, this is guidance only. No hard and fast rules. You will learn by doing. The worst that can happen is that you end up feeding the garden some coffee.
Second, safety first. Keep a fire extinguisher between the roaster and the exit from the area.
Seasoning the Roaster
I encourage new roasters to grab some “seasoning greens” from our website. They are inexpensive past crop. (https://millcityroasters.com/shop/coffee-beans/roaster-seasoning-odds-ends-blend-green/). If you didn’t grab some, use any high grown bean for this beginning exercise.
This serves two purposes:
- Seasons the drum. Do about 2-3 roasts where you roast and toss. Don’t drink these. These roasts help clean the drum of any residual oils from the manufacturing of the machine.
- Roasting the ‘throwaways’ will help you learn basic profiling of the bean. There is lots to learn. Patience. I write these notes after 9 years on home rigs and 5 months on a drum roaster. I am just beginning to learn – that’s one of the reasons coffee captured me years ago and continues to hold me.
- I actually encourage 20 roasts with seasoning greens — throwaways, to learn the roaster.
Turning on the machine.
- Turn on the gas at the propane tank.
- Next, the transformer for those of you who are stepping up the power from 120V to 220V. Turn the black knob and depress the white button.
- Turn on “power switch” (left switch on the control panel).
- Set the drum speed — RPMs – unlabeled (on the right-end side of the control panel) to about 75.
- Set the fan – “air volume adjusting” (right dial on the control panel) at about 35.
- Turn on the gas at the roaster (spigot or lever), immediately below the pressure gauge.
- Depress and release the electronic ignition – “roasting switch.” This will ignite the burners.
- Pre-heat the roaster without beans until you achieve about 400*F using a gas setting of about 5.0 kPa.
Artisan is free software. It provides a visual graphical representation of your temperatures throughout timed segments of our roast. It presents a “profile” when your roast is complete. We encourage its use and can be downloaded here: (https://code.google.com/p/artisan/).
When you are using it, don’t get trapped into being so attentive to the graph than you ignore the visuals and smells on the bean. Work that trier!)
Not using Artisan? Paper and pencil – record your time and temps but Artisan is easier. Just sayin…
Setting up the greens,
- Weigh out 1 kilo (2.2 pounds).
- Make sure the face plate is warm! Letting the machine warm up for 30 minutes assures that the heat applied during your roasting goes to the bean, not to warming a steel mass.
- For those using Artisan (and we encourage it), plug the USB connector into your USB port on your computer.
- Turn on Artisan.
- Make sure the environmental temp (ET) reads at 410*F or higher.
- Pour your beans into the top hopper (make sure the chute is closed).
- Open the chute and immediately start your Artisan profile.
- Make sure the chute is closed.
- Turn the “roasting switch” off by pushing down once on the “roasting swtich.” Do not turn off the gas at the blue handle. Just leave it.
- Let the roast “coast,” for 1.0 minutes with the gas “off” and then turn the burners back on by hitting the “roasting switch.”
- Turn the gas up to 5.5-6 kPa (as labeled on inner dial). This is the pressure at which I roast most high growns during the initial phase of roasting.
- At about 5.5 minutes into the roast, turn the gas down to about 5.0 kPa. Beans should be at a yellowing stage. Turn the air volume the air up to 45 on the dial.
- Start nursing the gas pressure down. You don’t want to fly into 1st crack. Beans are absorbing heat and will discharge that heat shortly during 1st crack (exothermic). You will want your gas to read about 2.0 when you enter 1st crack.
- You are striving to hit first crack (sounds like popcorn popping) between 8-9 minutes (390-395*F). Ignore the outliers and mark 1st crack when a series of cracks are heard.
- Keep your gas low — gas pressure at about 2kPa for about 2 minutes — or until the exothermic heat (stored up energy in the beans) exhausts itself and meter your gas higher as you continue to drive to 2nd crack. Rarely do I roast into 2nd crack. But for our seasoning roasts, we will press on.
- Second crack sounds like Rice Crispies. It is softer and less pronounced than 1st crack. Keep your heat going so that 2nd crack is controlled. Don’t let the roast get out of control.
- When you achieve a French Roast (great visual presentation on degrees of roast here at Sweet Maria’s: http://www.sweetmarias.com/library/content/using-sight-determine-degree-roast), TURN OFF THE GAS (labeled “roasting switch”), turn the “air volume adjusting” to its highest setting, and turn the drum RPMs all the way up (reads 100).
- Let the drum coast for 20 minutes (again assuring that your burners are off). Turn on the “cooling fan,” and the “coolant mixing” buttons. Your fan kicks on and the blades in the cooling tray will rotate.
- At the end of the 20 minutes, dump by lifting the handle on the left of the facing. Once the beans have all emptied from the drum, close the drum chamber. Let cool to room temp and feed the garden.
You did it! You can turn right around and do 4 more roasts as detailed above. Now, if you see ways to improve this guidance, add to it by “comments” or sending me an email at firstname.lastname@example.org.
Turn the machine off
- Turn your burners off (“roasting switch”)
- Wait until your ET is 250*F or less.
- Turn “power switch” off.
- Turn electrical power off on the transformer (black switch and white button).
- Close the propane valve at the tank.
- REPEAT, close the propane at the tank.
Need more detail? Long, complete article from the net is here: https://cdn.shopify.com/s/files/1/0238/9409/files/coffee-roaster-seasoning-roast-magazine.pdf
Still need more information? I recommend reading Scott Rao’s “The Coffee Roaster’s Companion,” my ready-reference. As a seasoned homeroaster and new drum roaster, I have found it invaluable. We have it available on our site: https://millcityroasters.com/shop/roaster-accessories/coffee-roasters-companion-scott-rao/
More help? Give us a call. We are here, long after you the North roaster hits your driveway. Dave Borton, BoldJava