Author Topic: SC/TO Profiles / Q&A / Tips & Tricks  (Read 119494 times)

Offline pwest

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #390 on: January 07, 2011, 05:22:34 PM »
I thought I would share a couple of general profiles that I have been using lately which net different results in the cup.  This is just the beginning of my experimentation, but these results are after over 100 successful(ish) roasts using my GG/UFO roaster.  The UFO has the heater disabled and the GG wiring is split so that the fan is on full all the time and the heater element is controlled using a router speed controller.  My batches are all 285g to keep the results more consistent.  I don't have the records in front of me, but the exact numbers are not the important part to me.

First profile - this has generated a slightly sweeter cup with a good overall balance.
Preheat to 350F as measure by the BT probe, let temperature stabilize for at least 5 minutes.
Drop beans in and switch heater to full.
When ET Probe returns to 350F adjust heat imput to coast until 4 minute mark.
Switch back to full until 400F ET, coast until 8 minute mark (BT is usually around 360F at this point)
Switch to full again until 450F ET and allow temp to raise slowly but not exceeding 475F. 
1C is usually around 12-14 minutes and roast is concluded between 3-4 minutes thereafter once I hit my final target BT (usually 425-430) pre -2C

Second profile - this profile tends to accentuate the brightness in the cup and is what I prefer for DP Ethiopians especially
Preheat to 400F as measured by the BT probe, let temperature stabilize for at least 5 minutes.
Drop beans in and switch heater to full.
When ET Probe hits 400F reduce heat imput to try and stabilize until BT Probe reaches 360F (this averages around 8 minutes on my setup)
Return to full heat until ET reaches 450F and reduce heat to a slow rise, not exceeding 475F.
1C is usually around 10-12 minutes and roast is concluded between 3-4 minutes thereafter once I hit my final target BT (usually 420-430F)

These aren't scientific by any means, but the results have been repeatable and enjoyable.  I have tried other suggestions and with modifications have settle on these two profiles as my starting points depending on what I want from a bean.  The second profile may be too much for a softer, lower grown bean, but I don't know for sure since all of my current inventory is high-grown, hard bean coffee.  Feel free to try this out and comment or make any suggestions or questions.


blzrfn:
Thanks for these profiles.  Do you log the BT temps?  Based on your description, I could come up  with approximate trajectories, but if you have some logs, I'd love to see them.

Thanks,
Phil

Offline chuckmartin

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #391 on: January 08, 2011, 11:38:50 AM »
Thanks to help from Peter, and loads of information I found here, I did my first two batches in my SC/TO today! I learned some things, and discovered "opportunities" for improvement. Having only previously roasted in an iRoast2, the very low volume was much appreciated, but it will take me some work to get the consistency of results I had with the iR2.

From what I read here, I decided to start with the TO warmed up at the 420F setting (the new temperature probe for my thermometer didn't arrive yet, so I'm flying blind!). After a 3-minute warm-up, I dumped in the beans and waited expectantly. Within a couple of minutes the beans were browning, and 1C started really fast. I turned the temperature down to 380F. Things happened so fast I didn't have time to record exact times, but I think 1C started before 6 minutes, and came out of the gate roaring. It roared right into 2C, without any noticeable transition, and I dumped the smoking beans around 10 minutes. The roast was uneven and darker than I intended, the darker beans approximating a French Roast, the lighter ones closer to the FC+ I would normally aim for (did I screw up the abbreviations?).

After cooling my first batch, I decided to do a second. This time I warmed up at 380F for 3 minutes and dumped in the beans. 1C started slowly just before 7 minutes, and slowly ramped up until it was rolling at 8 minutes. Again it transitioned into 2C without any real pause, at around 9:30, but it was much slower than the first time. I dumped the beans around 11-12 minutes. This second batch was a whole lot more consistent, and also was pretty close to FC+ I normally aim for, although maybe slightly darker.

I attach pictures of the two batches. It should be apparent that the second roast was much better.

During these initial roasts, I learned that the spacer that I made out of an aluminum yardstick (1" wide) needs to be attached to the SC, as the weight of the TO kept pushing it down during the first roast. The second time I sort of expanded it so it would maintain some outward pressure, and the TO didn't push it down. But I need to attach it so I won't burn holes through the thumbs of my gloves when I dump the beans.

I also learned that I needed a somewhat larger gap to allow the chaff to escape, and I bent it a little more, but I'm reluctant to bend it a whole lot before I can monitor the temperature. I learned my TO has a counter-clockwise rotation.

My cooling system can use a little work, but it worked reasonably well. I bought a $20 8" round fan at Ace Hardware, and initially put a steam basket (like a flat-bottom colander) on top of the fan. But it didn't seal against the top of the fan, and not much air was going through the beans. After fiddling a bit, I realized that the diameter of the steam basket matched that of the fan, and I just put the fan face-down on top of the basket. This worked great, except that I had a tendency to shake it so that beans hit the fan blades). It would be somewhat more convenient if I could just drop the steam basket in the top of a bucket, but this system works pretty well.

I'd appreciate advice on what to do differently next time. While I might have a thermometer probe, I might not. If I can fasten the spacer ring to the SC, then I won't need to spend my time making sure the spacer stays in place, and I can pay more attention to the smell and sound. I plan to drill small holes in the SC and strip, and screw it on (unless someone here convinces me that's a terrible idea!). The rest of my system seems to work fine, so I think I need to focus on controlling the temperature to slow down the roast somewhat. I think I need advice on:

1) Temperature of warm-up.
2) Time of warm-up.
3) Initial roast temperature
4) Is a change of temperature needed at 1C? If so,
5) To what temperature do I change at 1C?
6) Do I need to make any other temperature adjustments during the roast?

I'd appreciate any advice you can give.

Chuck

Tex

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #392 on: January 08, 2011, 12:14:11 PM »
Thanks to help from Peter, and loads of information I found here, I did my first two batches in my SC/TO today! I learned some things, and discovered "opportunities" for improvement.

<snipped>

Chuck

Howdy Chuck,
I pop-riveted the riser to my SC. It's holding OK, but the edge of the SC is plastic and I expect it to break eventually.

I have a 1/2" gap for the chaff to pass, and I bent the riser in a bit so it sticks into the air flow to gather chaff. It's similar to the one I made for my UFO/CO.

I try to hold temp at ~350°F for a couple of minutes to dry the beans, and I turn the power down to 50% at the first sign of 1st crack. There's enough heat in the beans at this point that they'll coast through 1st crack on their own. When I hear the last outliers of 1st crack I crank the heat back up to 100% for the duration of the roast. My roasts typically take 12 - 13 minutes to FC++.

Tex

Offline chuckmartin

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #393 on: January 08, 2011, 12:35:09 PM »
Thanks, Tex.

My spacer is too short to have the design of yours, although I had saved that same picture to use as a guide. But all I could find at Ace Hardware was a yardstick. Not the highly rigid kind that Susan got, but a thin flexible one. It was perfect except that is just meets with a 1/4" overlap (see the attached picture).

I was also worried about the plastic splitting. Your comment gave me an idea, though. I could attach two brackets to the spacer with bolts and springs, and bend them so they hook under the edge of the SC. That seems easy, it would be removable, and sturdy. It might take three, though, due to the gap. One on either side of the gap, and one opposite it. Don't you love it when simple problems are attacked with over-engineering? <g>

I'll try starting with a lower temperature and lowering it when first crack starts. Maybe my probe will get here soon. I just don't want to use the one I use for brewing beer.

Chuck

Offline peter

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #394 on: January 08, 2011, 12:37:08 PM »
Not to be critical Tex, but your spacer is waaaaay over engineered.  The springiness of the aluminum will keep the slot shut.  Simplicity should rule.





I found the 1/16 x 1 1/2 x 4' aluminum at Lowe's.


Chuck, I'll bet dollars to donuts you have the bottom heater still on.  I know a lot of people do, but unless you really need that much heat and want to do huge roasts, I'd suggest either disabling it or putting it on a switch.  Having a t-stat in the SC and a t-stat in the TO, each acting independently makes it hard to follow an exact profile.  I'd guess that's why your roasts roared into 1st and kept right on going into 2nd.

Sorry for the huge photo.
« Last Edit: January 08, 2011, 12:39:27 PM by peter »
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Offline chuckmartin

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #395 on: January 08, 2011, 02:19:44 PM »
Quote
Chuck, I'll bet dollars to donuts you have the bottom heater still on. 

Thanks for the suggestion, but I actually removed the entire heater assembly. Wish now I'd taken photos.

Chuck

Offline peter

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #396 on: January 08, 2011, 02:26:57 PM »
Quote
Chuck, I'll bet dollars to donuts you have the bottom heater still on. 

Thanks for the suggestion, but I actually removed the entire heater assembly. Wish now I'd taken photos.

Chuck

You'll get the hang of how your roaster reacts to ambient temps and bean loads, and you'll learn how to anticipate.  That's the key to roasting, is knowing how early to turn things up or turn things down.  You may not need that much preheating either.

I don't recall if you have an accurate means of measuring temps.  ?

I'll dump my beans with the heat full on, and when the beans are at 280, kill the heat and let them coast up around 300.  Then I'll modulate the heat for a bit so that they hover around 300 for 3 min.  Then it's heat full on, until 344, heat off and let them coast into the low 350's.  Modulate heat to let them sit at that point for 2.5min., then heat full on 'til the low 400's.  Then modulate the heat for a slow, steady rise through 1st.  If you get that last part right, you can get through 1st completely and stop it right then, or get a slow, steady increase for a well-developed C+.  They say that stretch between 1st and 2nd is helpful for developing body.
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Offline chuckmartin

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #397 on: January 08, 2011, 02:41:53 PM »
Quote
You'll get the hang of how your roaster reacts to ambient temps and bean loads, and you'll learn how to anticipate.

That reminds me of something I thought of when trying to keep my spacer from collapsing but later forgot. I need to include the ambient temperature in my log. I used my iR2 inside, so ambient temperature really wasn't an issue. But today I roasted outside in 40F and somewhat windy conditions. That is something I'll have to account for.

Quote
I don't recall if you have an accurate means of measuring temps.  ?

I mentioned that I had not yet received a new probe for my kitchen thermometer that I ordered for just this purpose. I'll probably hang it through the hole in the spacer. But for now, I'm flying blind.

I suspect that my TO heats faster than most of yours because it's brand new and not coated with coffee residue. And that I won't be able to get predictable results without monitoring temperature. At least not while the process is so new to me. I did get to where I could judge when a roast was done in the iR2 by sound and smell (amazing I could hear anything over that noise, but I could). I probably will be able to dispense with the thermometer after I've done 200+ batches with the SC/TO, too. OTOH, I never stopped verifying the temp on the iR2. I don't understand why comments on this board regarding the iR2 are so universally derogatory. It served me well, and even if my SC/TO turns out to be better once I get the hang of it, I would still recommend the iR2 for a beginner who prefers ready-made automation with good control. But I do hope I'll soon be able to produce better roasts with my SC/TO. My first to are significantly inferior, but I have hope.

Tex

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #398 on: January 08, 2011, 03:25:54 PM »
Quote
You'll get the hang of how your roaster reacts to ambient temps and bean loads, and you'll learn how to anticipate.

That reminds me of something I thought of when trying to keep my spacer from collapsing but later forgot. I need to include the ambient temperature in my log. I used my iR2 inside, so ambient temperature really wasn't an issue. But today I roasted outside in 40F and somewhat windy conditions. That is something I'll have to account for.

Quote
I don't recall if you have an accurate means of measuring temps.  ?

I mentioned that I had not yet received a new probe for my kitchen thermometer that I ordered for just this purpose. I'll probably hang it through the hole in the spacer. But for now, I'm flying blind.

I suspect that my TO heats faster than most of yours because it's brand new and not coated with coffee residue. And that I won't be able to get predictable results without monitoring temperature. At least not while the process is so new to me. I did get to where I could judge when a roast was done in the iR2 by sound and smell (amazing I could hear anything over that noise, but I could). I probably will be able to dispense with the thermometer after I've done 200+ batches with the SC/TO, too. OTOH, I never stopped verifying the temp on the iR2. I don't understand why comments on this board regarding the iR2 are so universally derogatory. It served me well, and even if my SC/TO turns out to be better once I get the hang of it, I would still recommend the iR2 for a beginner who prefers ready-made automation with good control. But I do hope I'll soon be able to produce better roasts with my SC/TO. My first to are significantly inferior, but I have hope.

One other thing - I've rewired bu CO so the element has no tstat. Cutting the power back at various temps proved problematic until I got rid of the tstat (too much dead band).


Offline sea330

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #399 on: March 06, 2011, 12:57:24 PM »
Just a look at what I am doing,I have removed all the teflon, built a metal shaft and stir arm and also upgraded the motor to a 30rpm motor. I am using a GG 1400 watt turbo oven.loaded with 18oz of greens to see how the beans moved seems to work great, haven't tried with heat yet need to fab the 1"1/2 spacer with a tiny damper for chafe removal.Now I will try to down load some pics so you can see whats going on.Haven't figured out how to mount temp probe to measure bean temp. Don't need pid control just need monitoring Rich

Tex

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #400 on: March 06, 2011, 02:11:34 PM »
Just a look at what I am doing,I have removed all the teflon, built a metal shaft and stir arm and also upgraded the motor to a 30rpm motor. I am using a GG 1400 watt turbo oven.loaded with 18oz of greens to see how the beans moved seems to work great, haven't tried with heat yet need to fab the 1"1/2 spacer with a tiny damper for chafe removal.Now I will try to down load some pics so you can see whats going on.Haven't figured out how to mount temp probe to measure bean temp. Don't need pid control just need monitoring Rich



I use a 20 gauge beaded-end thermocouple. I cut a notch in the riser so it'll hold the t/c in place, and looped the wire to keep enough tension on the tip to keep it buried in the beans.

UFO-CO thermocouple placement

Offline sea330

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #401 on: March 07, 2011, 06:49:10 AM »
Hi great setup just interested on what rpms this runs.I have seen these ice cream makers at goodwill may pick one up to build something on the same lines.What kinda stir arm did you fab.very good idea.Thank you for your post best regards Rich

Offline nimbus

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #402 on: June 16, 2011, 09:34:49 AM »
Hi Fellas,

Well, I've been toying with the SCTO idea for a year or so, and finally, at the thrift shop last week, the SCTO gods were looking after me and put a Boxed up Stir Crazy right next to a Turbo Oven right on a shelf. I couldn't resist.

I had been casually looking - again on and off - and this is the first time I've seen either of the two in a thrift shop. They were overpriced (9.95 and 14.95), but bought 'em.

So now on to thinking about this new project.

Question: My SC is from 1977. It looks like all metal shaft. Do I still have normal temperature worries there, that I have seen others talking about? Any other considerations due to the vintage of this model? (yes, it works, though looks like low RPM. What is normal RPM?)

Going to get some aluminum, disconnect the heater, and give it a go. Then think about the stirrer arm. I guess I'll pick up a copper end-cap to put over the shaft, just in case.

Well, off to teach. Talk to ya'll soon. I'm sure some questons will come up soon.....

-Nimbus
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Offline chuckmartin

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #403 on: June 16, 2011, 09:41:39 AM »
Quote
Question: My SC is from 1977. It looks like all metal shaft. Do I still have normal temperature worries there, that I have seen others talking about? Any other considerations due to the vintage of this model? (yes, it works, though looks like low RPM. What is normal RPM?)

Going to get some aluminum, disconnect the heater, and give it a go. Then think about the stirrer arm. I guess I'll pick up a copper end-cap to put over the shaft, just in case.

I have an old SC with a metal shaft, and I have neither replaced it nor covered the top with a cap. I would guess mine is roughly 10 RPM. And I have not found the need to modify the arm at all. Works fine. The motor is rather weak, so I suspect I might have difficulty if I added anything that increases resistance anyway.

Chuck

Offline peter

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Re: SC/TO Profiles / Q&A / Tips & Tricks
« Reply #404 on: June 16, 2011, 09:47:32 AM »
Hi Fellas,

Well, I've been toying with the SCTO idea for a year or so, and finally, at the thrift shop last week, the SCTO gods were looking after me and put a Boxed up Stir Crazy right next to a Turbo Oven right on a shelf. I couldn't resist.

I had been casually looking - again on and off - and this is the first time I've seen either of the two in a thrift shop. They were overpriced (9.95 and 14.95), but bought 'em.

So now on to thinking about this new project.

Question: My SC is from 1977. It looks like all metal shaft. Do I still have normal temperature worries there, that I have seen others talking about? Any other considerations due to the vintage of this model? (yes, it works, though looks like low RPM. What is normal RPM?)

Going to get some aluminum, disconnect the heater, and give it a go. Then think about the stirrer arm. I guess I'll pick up a copper end-cap to put over the shaft, just in case.

Well, off to teach. Talk to ya'll soon. I'm sure some questons will come up soon.....

-Nimbus

Those prices might be high for a thrift shop, but still a bargain.

The rpm is generally low, I'd guess around 30.  If you disconnect the heater, you might think about putting a switch on it; there are times when a little extra heat will benefit; the heating element on the TO is slow add heat.  For the periods in the profile when you want to pause (around 350 maybe) and then when it's time to head for 1st, you'll appreciate being able to move things along by switching the bottom heat on.

I'm going to suggest leaving the last 1/3 of the spacer unattached w/ a .5" overlap.  The springiness of the aluminum will keep it closed, but when you want to let the chaff out, or modulate the temps and let some of the heat out you can just prop the spacer open.

A tip for the copper cap that I wish I would have used; cut a notch on one side where it'll fit over the stirring arm, but on the other side make it a hole that slides over the end of the stirring arm on that side.  That way it'll never fall off when you're dumping the beans.

The stock stirring arm doesn't work well for either the larger batches or the smaller ones, but will work well for mid-range batches, say 300g.

Good to see you posting Nimbus.
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