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Popcorn-Popper -> Coffee Roaster Mod
the-few writes "Tom Gramilas (Toms-roaster@columbus.rr.com) created a computer-controlled coffee roaster using an old West Bend Poppery I popcorn-popper (popular among home roasters with a modding mindset), a few thermocouples, and an old DOS computer. The code he wrote to control it is available from his site on request, and uses a flexible control algorithm to control roasting segments. Pictures and roasting profiles included."
No, but this article is about the construction of a computer-controlled COFFEE ROASTER.
Notice:
created a computer-controlled coffee roaster...
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I'm glad you asked:
Sweet Marias.
I have ordered from them on three occasions. They have a review on everything they sell which describes in great detail on what each tastes like.
I use the Heat Gun/Dog Bowl method of roasting myself. Works every time.
He's an engineer, not an embedded systems guy. Two HP power supplies with GPIB and an internal NI GPIB card are about $1500 worth of hardware. I2C ADC's and a Coldfire would have cost him about $30.
Classic system though.
'Be always mindful, even when ditch-digging.' --D. T. Suzuki
Been buying green beans from http://www.sweetmarias.com/ for years. And years. And, roasted coffee with a West Bend Poppery II for years. Use an Alpenrost now - but plan on a BBQ setup using an RK Drum. Yeah - do a google for green coffee and you'll come up with a few sites. The difference between this and the sludge from stores is nothing short of remarkable - no bitterness, tastes kinda like it smells - what coffee should be like.
Too bad the site isn't ran off of a home cable modem. It's ran off of Road Runenr's webspace for it's home users.
I always went by sound of the beans (first and second crack), and look. I have something similar to an air popper, an IRoast
I find that for each batch of beans, the ambient conditions, exactly how much I put into the roaster, and any number of random factors contribute to how well the roast comes out. No matter how much control I have over the interior of the roaster (and my roaster lets me set up to 3 different temperature points to achieve during the roast), I always wind up programming the last stage of roast to go longer than I need to. I do this because the roasts are easier to measure by eye/ear for 'doneness'. I can guestimate approximately when it will be done by time, but it never seems to come out the same.
I wonder if all the TC's, etc, really get you a better roast, or if it's just cool to say "Look what I did!"
His actual hane is Tom Gramila (no "s") and
he is professor of Physics at Ohio State.
While I do not use the computer setup, I do use a $10.00 corn popper, and high-quality green coffee beans.
If you are looking around for green coffee beans, just ask at coffee shops that are not like Starbucks. You will eventually find one that roasts their own beans.
When you buy green beans, they will usually be less expensive than the pre-roasted variety. Also, remember that during roasting the beans double in size.
Note: the popcorn popper should be of the "swirl" type. That is, the vents at the bottom of the roasting container should cause the beans or popcorn to "spin" while roasting. Do not use one that channels the air straight through.
Fill the "butter warmer" so that it is level with green beans, then pour these beans into the popper.
Plug the popper in.
Now - one warning - roasting coffee beans produce LARGE volumes of smoke, and most of the smoke occurs during the end of the roasting process. You cannot put the roaster outside unless it is a very warm day (the air will not be warm enough to roast the beans properly if the incoming air is cold). So, you need to keep the roaster at room tempurature. What I do is open a window, and stick the output part of the popper out the window, while keeping the rest inside. You can also use the fume hood of your stove.
Once you turn the popper on, the beans will begin to spin. After a min or so, the "chaff" (bean covering) will begin to fly out of the popper. Collect this in a bowl to prevent a mess, or do as I do and point it outside.
At 3-4 min, the beans will have gone from green to red or yellow, and from there they begin to progress to brown.
During this process you will start to hear the beans cracking and popping. This is called "First crack" and is entirely normal. Finally, as the beans get darker, monitor them so that you can stop the popper when the beans are the roasting color you desire. (For me, this is about 8-10 min total). Finally, near the end of the roasting process, the beans will begin to pop and crack again, (known as second crack) and small round discs will flake off the beans. (Due to escaping moisture I belive). This is around the time that most people consider them well roasted.
Now - unplug the popper (IT IS VERY HOT NOW! BE CAREFUL!!!) and dump the beans into a container. I use a glass jar. They will still be smoking. I cover the container with saran-wrap and let it sit 24 hours. I have read that the CO2 "gassing out" from the beans can break mason jars that are sealed in with hot roasted beans in them. (It could be myth, I dont know, never saw it myself).
You can use the beans right away, but I reccomend that you wait a few hours to grind them. About 24 is best. (Freshly roasted beans don't yet have a full flavour - they are very "flat" waiting 24 hours greatly improves the experience.) The beans will keep their excellent flavour for about a week - after that, the oils will start to evaporate, and you will end up with basic storebought beans.
This sounds complex, but it is pretty simple. And in the end you have incredible coffee - and it costs less!
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The hardest part about this setup is finding a working original West Bend Poppery. You will probably only find the Poppery II, which has only 1200 watts, not 1500 and no on/off switch. I use those with only one mod: A hole drilled in the lid to accomodate a thermometer. Monitoring temperature that way is a bare minumum to control the process. You need one that goes up to 550 degrees fahrenheit. Most don't.
Fresh roasted coffee is the best kind you will ever have. Even people who thought they didn't like coffee can change their minds. Unlike at Starbucks where they burn the coffee until it all tastes the same, you can roast any way you like, and taste the difference between one coffee and another if you do it yourself.
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Just a few things to add - try your local thrift stores for hot-air popcorn poppers. We got ours for generally under $3 each. We use a measured half-cup of beans per batch - more tends to spit beans out, and less goe slowly as the beans do far more spinning than roasting. Cover the "butter" holder - we used some old circuit board :) With this open, most of the air vents through it, and roasting takes longer. Use a burr-style grinder, instead of a blade grinder like the Krupps. Burr grinders produce a far more controllable and uniform size of ground coffee. Oh, and you just might want to throw away your creamer and sugar once you get into roasting. Real coffee doesn't need "enhancement."
A few good sites to check out:
Sweet Marias has beans, equipment and instructions. Very good.
Coffee Bean Corral has equipment, beans, and some software they call the coffee matrix, to help you choose the perfect bean for your needs.
Coffee Wholesalers has beans and equipment. A good place to start buying beans online.
Hope you have fun! And you'll never tolerate stale, bitter, lifeless coffee again.
Lemon curry?