Well this is the 2nd roast on the newly constructed Lowes Waste Can Drum 8" dia. by 13" long. After removing the Alpenrost style rollers. and inserting a rod thru the drum, connected via spider coupling at the 50 rpm motor and running in a solid brg. at the other end. I loaded 450 grams of Mexican Organic El Oliva in a cold drum, Grill was pre heated to 500 degrees. After inserting the drum and switching on the motor, closed the lid the temp was at 300 degrees. 1 first 2 min soaked at 300 heat on low 2 at the 4 min mark 340 turn heat to med. 3 at the 6 min mark 450 this is environment heat not bean 4 at the 7 min mark 460 5 at the 8 min mark 470 6 at the 9 min mark 480 7 at the 10 min mark 500 cut heat to med low 8 at the 11 min mark 510 9 at the 12 min mark 525 first crack at the 12:30 cut heat to low 10 at the 13 min mark 460 11 at the 14 min mark 450 at 14:30 heat to high to push to 2nd crack 12. at the 15 min mark near 500 2nd crack begins, cut heat completely off. 13 at 16:30 rolling 2nd dumped roast 14 roast cool at the 17:30 mark Dark Mahogany brown shinny no oil is what I call French. Conclusion IMO the 50 rpm motor is to fast for a 8" drum, it tends to sling the beans instead of tumbling them. The roast came out extremely even but was hard to hear the 2nd crack for the noise of the beans being agitated. It was also hard to see the beans rotating that fast. The drum speed needs to be reduced to 25 max. I'm thinking 15 to 20 would be ideal for this size drum. I'm happy with the coffee, but its really hard to keep up with the cracks with the noise of slinging beans. A rheostat is in order or some pulleys to slow this thing down. Gas grill drum roasting is a hoot I love it but I keep running out of Mason jars, and what do you do when the freezer is full:O) I really need to start selling coffee at the local Farmers Market. Hey I beleive thats how Oaxaca Charlie got started. excuse me I have to drink a lb of coffee before Monday. Ron rnkyle Home Roasting in SC |
Way to go Ron. so the roller idea was a bit noisy. Hmmmm, guess I need to find another way to allow one end of my drum to be free of the axle rod. I've got a Melitta Aromaroast roaster I am thinking of attaching to my grill to provide convection air currents to aid the roast. By pre-heating the input air to roasting temps, I can have heated air blowing in and not significantly mess up my roasting temps. When I set it up like this, I also plan to use an exhaust tube, possibly with a small powered exhaust fan to help suck out the smoke. Input air and powered exhaust might make the smoke issue a bit more tolerable, and allow me to vent it to the outside rather than blowing it out with a fan. Here's a recent successful roast curve (Kenya AA) with my grill roaster. TIME Temp Bean temp START 550F 85F (ambient air temp appx. 85F) 1:00 460 160 (roaster temp stabilizes) 2:00 460 225 3:00 460 265 4:00 460 275 5:00 460 290 6:00 465 310 7:00 470 320 8:00 470 335 9:00 478 350 10:00 485 365 11:00 485 375 12:00 490 385 13:00 495 400 14:00 500 410 15:00 500 420 15:30 500 425 (1st crack) 16:00 500 430 17:00 500 438 (reduce heat) 18:00 485 445 19:00 480 448 20:00 465 448 (second crack) 20:30 465 449 (pull roast and forced air coolin 3 minutes) Ed Needham To Absurdity and Beyond!http://www.homeroaster.comed **************************************** ********************************************** |
Ed, I'm always curious about how approximate profiles without taking bean temperatures (hard to do in the open environment of grill-top, heat gun roasting). I'm interested quantifying and replicating my own roasting in ways that are consistent with taste and theory. I've been thinking about the ratio of time to first crack to time to second. Just as a example, your profile below is roughly 3:4. ED'S PROFILE <Snip> And Ron's profile is roughly 4:5 ---- RON'S PROFILE <Snip> My "default" profile (adjusted for bean's, chance, and whim)is 6.5 minutes to first, and 9.5 minutes to second, or roughly 2:3 Any thoughts about this RATIO as a useful metric somewhat (though I realize never entirely) independent of length of roast? Martin ===== Martin Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month!http://sbc.yahoo.com |
On 5 Jul 2003 at 18:10, HeatGunRoast wrote: <Snip> I don't think it is. To some extent the times trade off. For instance, I used to spend 4 minutes going to the first crack, then five minutes after that. Now I spend 7 minutes going to the first, and four minutes after. This gives roughly the same flavor profile, but more consistently, and with greater detail -- like a better resolution photo. If I had to give a rule, I'd venture for each extra 2 to 2 1/2 minutes from 300F to 400F, one can reduce the time after that by about a minute. Jim |
Another question, probably answered and debated at length in the drum/fluid bed discussions, but I guess I'm slow to catch on. Is there something that you fundamentally prefer about a 12 minute ramp to first crack (as with your recent profile in response to Ron, over the 5 to 7 minute that you mention below? Is this a bean-specific decision? Or is it a matter of small consequence and mostly a function of how long it takes your roaster to get the beans up to temp? I keep pressing to understand what I can here (theory and principles) because although I can accurately measure time (duh!), and I think I have a good sense of rate-of-ramp, I can only infer actual temperatures by cracks and other sensory inputs. Martin |
On 5 Jul 2003 at 19:20, Martin Lipton wrote: <Snip> I use a 7 minute ramp to the first crack, 2 minutes to 290, and 20F/min after that. Then 4 minutes to finish the roast. The 12 minute ramp will be used when I clone Ed's drum roasts. This is much more a matter of taste than science. The basic difference between a drum and air profile is that the mass of the drum acts as a heat capacitor, delaying its delivery to the beans. This creates a roughly straight line roast profile. An air roaster usually delivers air at a fixed temperature around 480F to 500F. The beans heat quickly at first, then stall out as they get above the first crack. This yields a very curved profile. Ed has a lot of graphs on his site. Profile roasting requires monitoring the time and temperature, and varying the heat to achieve a preset temperature to time graph. If the microchip or operator is doing something else, it isn't profile roasting. Mike and I, as well as many of the less garrulous list members, have air-roasters set-up to do this Most, but not all, of us prefer to follow a straighter drum-like profile than unmodified airroasters, although we usually start faster than drums, and finish slower. Stay tuned to the "Ed's thrown the Gauntlet" posts to see if our purely empirical groping towards a decent profile has come to something, or whether an old-fashioned drum roast by an experienced roaster will beat our pants off. As to science, there isn't much. The Maillard reactions begin at 290F and transform the proteins and sugars in the bean. There's about five major branches the reaction can take, with up to a hundred specific chemicals in each branch; these are all parts of the fruity origin flavors. Above 400F, straight caramelization begins involving only the sugars and producing the roast flavors, while mellowing and eventually degrading the origin flavors. Unfortunately, the profile of exact reaction pathway to temperature and moisture content (the other major determinant of maillard reactions, and another possible source of drum/air differences) is unknown. So one can't say "I want more of that nice pear flavor, 3% more moisture, 20 seconds less at 360, and 15 more at 285 ought to do it" I was fully expecting to find information like this when I started reading coffee chemistry books. But scandalously, no industry paid researcher is looking to find this out. Most coffee research is how to use industrial distillation methods on coffee (it's gotta be "pure") to get "coffee flavors" that can be sprayed back into instant coffee powder. That's why the recent "roasting dissertation" struck many of us as so amateurish, despite the hi-tech equipment used; the food scientists are basically amateurs at roasting. Jim |
I can change the profile I posted significantly if I put the beans in a pre-heated drum. I can blast through first crack that way and the results, in my opinion, are not any better. Plus, I have to handle the heated drum twice that way. Not a huge problem, but I've melted the plastic bean baggie more than once on the 500F+ spit rod while pouring in the beans. My second row of temps is from a 12" dial thermometer stuck through a hole in the top of the grill, through the opening on the end of my drum, and directly into the rotating bean mass inside the drum. I twisted one thermometer all to heck one time while I was experimenting, trying to get it in there while the drum was rotating. That big horse of a gearmotor could probably do the same for 3/8" steel rod. I have to be really careful when that thing is running so as to not get tangled up in it. I would like to bring my roast time down to around 18 minutes, but so far, without preheating the drum, it has been elusive with a five pound load. I upped the start temperature to 550F, knowing it would allow a bit more thermal inertia when the cold beans and drum are inserted, but it only shaved about a minute from the overall time. Pertaining to ratio. It looks as if the actual 'ratios' are all in the same ballpark. I don't see a 3:20 or a 13:4, but a 2:3, 3:4 and 4:5. Time to first is drastically different though. Mine is 15:30minutes, Ron's is 12:30minutes, and yours is 6:30minutes. Time between first and second crack is also significant, with yours being actually longer than Ron's, even though his time to first was almost twice as long as yours. Mine was 4:30minutes, Ron's was 2:20minutes, and yours was 3:00minutes. That, I find interesting, and some light will 'hopefully be shed this weekend as myself (grill drum roaster), Jim Schulman (modded FR), Ted Simpson (gas fluid bed roaster) and Mike McGinness (modded Rosto) all roast the Kenya AA Mika using several different roasters and profiles. We'll post our results here, and probably on my web site (if the others agree to allow their hard work to be displayed there). Ed Needham To Absurdity and Beyond!http://www.homeroaster.comed **************************************** ********************************************** |
snip from Ed's reply: < so the roller idea was a bit noisy. Hmmmm, guess I need to <Snip> Ed I believe the rollers would work, if the rpm was a lot slower, and if the can was very round. The can I used was way out of round and getting the rod directly in the center of the can was a bit difficult along with the spring from the weight, it made for a bouncy ride for the drum. the steel axle wheels also wanted to squeak, maybe some very high temp grease, Food grade may help solve that. I'm like you in the aspect of not having the rod go all the way thru the drum. I'm working on a bronze brg with a flip up cap to hold the drum in place, it will probably need two and that means quick action at the end of the roast to release the brg. caps. I'll keep on experimenting and if I hit on a viable solution I will post it. Ron rnkyle Home Roasting in SC |
> The basic difference between a drum and air <Snip> Jim, For commercial drum roasters this is true, but not for home drum roasters. Both the HotTop and Alp use perforated drums. The Alp's drum is very light and has less heat mass than the 1/2 pounds of beans. So in these machines the drum's thermal mass has very little effect on the curve. The largest factors, I think, will be the size of the heater and profile programmed in the chip. Dan |
On 6 Jul 2003 at 7:19, Dan Bollinger wrote: <Snip> <Snip> Hi Dan, I sometimes think there's a lot less to these profile chips than meets the eye of the marketing department. There's certainly lots of variation in both roasters from ambient temperature and voltage changes. Even my little FR chamber needs one roast to fully warm up, while in the Alp and Hottop, not just the drum, but the entire mass of metal has to heat before everything reaches equilibrium. So I still think their natural, uncontrolled profile is probably a good deal more linear than an airroaster's. Jim |
I have found that on my Zen roaster also. Each test is getting it quieter. So far I am using oillite bearing just outside the main roast chamber (I assume this will not help you much) but have also found in my searches Rulon brgs that can theoretically handle roast temperatures and should be much quieter. Sometime around 04:36 7/6/2003, Ron typed: <Snip> -- John Nanci AlChemist at large Zen Roasting and Blending by Gestalthttp://www.dreamsandbones.net/blog/ |
How's that coming along? Any updates? John Kangas <Snip> Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail |
So does this mean that you're up and roasting with the Zen roaster? Did I miss some posts on it? Also, where are you purchasing your bearings? Dave Lowe |
Sometime around 10:54 7/7/2003, john kangas typed: <Snip> No real updates. I picked up and installed the components for my rollers, i.e. double ended threaded bolts, oilite bearing and nuts (had the rollers already). Aside from that, I am still in the process of getting some porcelain for the insulators. Mainly, the project has slowed a little (but life has not) <Snip> -- John Nanci AlChemist at large Zen Roasting and Blending by Gestalthttp://www.dreamsandbones.net/blog/ |
Sometime around 11:33 7/7/2003, Lowe, David typed: <Snip> No, it is not quite up and you did not miss any posts. The bushings are from Applied Industrial out of Roseburg, Oregon, although I believe they said they have a Portland division. <Snip> -- John Nanci AlChemist at large Zen Roasting and Blending by Gestalthttp://www.dreamsandbones.net/blog/ |