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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."
The code better be Java.
Dear Slasdot Editors,
Please setup caches before posting stories running off of home cable modem website spaces.
The story is irrelevant/pointless in most cases, if TFA cannot be read to begin with.
Thanks,
Slashdot Reader
Sig it.
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.
I actually have four thermocouple in the rig: each of the TC's in the roaster has a reverse connected TC attached to it, This helps to eliminate stray thermoelectric voltages, and is, I'm told, the most accurate way to use a thermocouple. Because of the reverse junction thermocouples, the voltmeters sense the difference between room temperature and the temperature of the sensor. The use of high quality voltmeters here, with low DC offsets, is important since the TC's generate only 22uV or so of signal per degree F.
That's an unusual way to hook up TCs, unless you put the extra TC in an ice bath (for the ice point). All TC meters (as opposed to generic voltmeters) have an artificial ice point voltage generator inside.
In the design of this roaster, the extra TCs shold be in an distilled ice/water bath, otherwise the roaster temp depends on room temp, which is not what you would want. The roaster temp should be independant of the room temp variations (that is the whole point of a control system.)
The other choice would be to use a surplus ISA based TC meter board (which has it's own ice point) in the PC, then you would only need 2 TCs and these would read the temp directly.
Still, I think I speak for all of /. when I say that this project deserves praise and admiration for not only its pointless complexity, (really, a requierment of any GOOD project) but also for the use of very expensive and obscure (GPIB voltemeters and an A_D converter? WTF?) components.
Sort of reminds me, in spirit anyway, of the weed burner I made out of an oil burner for a house furnace, and the snowblower made from the front half of a subaru station wagon...
If the ends justify the beans, yes.
Does it use HyperText Coffee Pot Control Protocol, as defined in RFC 2324
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!
Try to hack my 31337 firewall!