Roast and Learn Together - February 2015

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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TomC
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#1: Post by TomC »

I'm excited to explore the new lot of Rwanda Karongi Gitesi from Sweet Maria's. It's a consistently impressive coffee in years past. It pops up in the "what's wow'ing you" thread with good comments and from T. Owen's description, this year might even push the "wow" envelop further. The aromatic descriptors are quite enticing.

I'll be looking to see what we can find roasting this for espresso as well. But I think it will be a win-win either way.
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TomC (original poster)
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#2: Post by TomC (original poster) »

I fired off a quick sample roast of this the night I got it and it revealed a complex, sweet cup with plenty of intensity in the Tootsie-Roll sweet caramels. I get where the Sweet Maria folks are finding pineapple upside down cake. There's a lot going on.

But I'm a bit stymied by my first batch, although interesting early on, I'm noting a very unpleasant soap note in the finish today that seriously had me scratching my head. I changed my prep method (and re-washed everything) from brewing with the Kalita to just doing a cupping and still noted a hint of it lingering in the finish. I can't tell if it's just a tainted palate for a while or not though, since even while sitting here typing this an hour later, I still can sense the feeling like I got caught swearing as a little kid :| The first batch today, I pushed the extraction too far with a rather fine grind though. It was barely notable in the cupping method and could be my tainted palate speaking.

I won't bother sharing my first profile, but I'll fire another batch up tonight after the game. I want to stretch my development phase more than what I did initially. The greens aren't pretty like a washed central at the end of drying. It's early to say, but they seem to need a high initial heat level.




Here's a new batch, 230 grams, one day post.



2/6/15- Kalita Wave 204°F 17:1-3.5 minute brew time.
It's still a complex and interlaced coffee. Flavors and aromatics don't jump out in singularity, but it's impressive nonetheless. I still am pretty convinced there's more to it that I haven't nailed perfectly but it makes a wonderful cup.

2/13/15- Clever dripper 205 F, 20g/ 300g brew.

The coffee has softened and become more raisin like, less sherry like. Some of that alcohol/brandy notes have diminished. Hopefully now it will give a sweeter more balanced shot, because previous attempts were to much like a liquor. Tonight I'll run a few more profiles and see what it does at more development. I could see this bean adding some nice character to a clean Brazilian and used as a blend for espresso. Might explore that route a bit more later on.

Next batch will be done at a higher charge temp, shorter drying phase and leave as much time for development as possible without pushing it too dark. The dry grounds are rich, slightly savory, complex and with a hint of coriander. In the cup the aromatics are mild cinnamon and raspberry in the back with a sweet caramel-y tone. Sweetness is great; it's dark maple syrup all the way. Acidity, mild, crisp malic. Flavors are cola and pecan and a lot of complexity. Thin mouthfeel and a sweet, apple-like finish. It's sitting around a 90pt cup right now and I imagine it will pick up with some work and be more impressive as an espresso due to the complexity and wonderful caramelization components.

The roast impressions tell me it likely can be taken in a wide range of development, and it needs a firm hand on the heat application. Who knows, maybe it would be even more interesting in a melange of different levels of roast.
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cannonfodder
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#3: Post by cannonfodder »

My big box of love just arrived from SM. I may get to roast a batch this weekend.
Dave Stephens

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NoStream
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#4: Post by NoStream »

I roasted a couple batches on Wednesday and cupped them last night.

My main focus here was achieving a declining RoR in the development phase of the roast. I typically extend the drying interval to allow for a lighter finish.

Green coffee: Rwanda Karongi Gitesi
Green coffee supplier: Sweet Maria's
Green coffee density: High
Green coffee processing: Washed

Roast date: 2/4/2015
Roaster: Quest M3

Charge weight: 150.0g
Charge temp 420 F MET, ~400 BT

Moisture loss: 12.0% (roast 1), 11.9% (roast 2) (low, but it's a dry winter)
"Dry"/Ramp/Development: ~5:00/3:15/1:30 (vs. 5-3:15-1:45 goal)
FC-start temp: ~383-385 F (ever-so-slightly higher than usual; it's winter and it's dry)
Finish Temp: 403 F

(full resolution at http://imgur.com/a/SGL56)



Taste notes, from roast 1

From others: universally agreed to be super sweet and quite full-bodied; a few picked up on a certain savory character but agreed that it probably wasn't underdevelopment

From my notes, of a 12:210 (1:17.5) V60-01 at ~1.4 %TDS, 22% extraction
Dried fruit (raisin), berry (cherry and cranberry), intense rustic sugar (brown, molasses), savory (garbanzo beans, herbaceous-vegetal, both savory and slightly papery), spice (cinnamon and cardamom)
Thick mouthfeel, slightly soapy

--

Critiques are always welcome. Right now, I'm finding a couple parts of the development phase challenging. Namely, I'm trying to achieve declining RoR in development but also extend development to 1:45 to caramelize sugars. It's easy to reach 1:45 but bake the roast a bit or to have a faster development phase with declining RoR. It's hard to hit both targets.

---

Next roast planned: probably slightly longer drying time to smooth it out a little more, development to hit 1:45 even if it means dropping a couple degrees hotter. This is a nice coffee but also one where I am not necessarily bothered by a little roast character and, say 13% WL instead of low 12's.

Full-res at http://imgur.com/R71h4EX,SxbWMZe#0

Roast 1 is an attempt at the above plan. Slightly longer development, still with a longish dry and quick ramp. 5:30-3-1:45 essentially. 12.8% WL

Roast 2 is a more Rao-styled approach. I say Rao-styled because it's fast-start, slow-finish with an approximately declining RoR. 13.8% WL


From cupping (1:18, 203 F), profile one above is more sweet, clean, and tartaric, plus a bit of citrus. Two focuses more on citrus and has a bit more caramel.
From V60 brewing (1:17, 203 F), profile one is more sweet and delicate, more crisp. Profile two is fuller and more caramelized.


Espresso, 2/18/2015, 7 days post. I wanted to examine extractability/solubility through espresso.
Roast 1 above, the slow-start profile did not pull well. The first shot was 15 in 34 out in 30 seconds, the shot was salty and peanutty (suggesting somewhat incomplete development). Longer time shots got a bit medicinal. I do need to try pulling longer in a longer time, but typical parameters on a typical machine (CC1) don't work well.
Roast 2 above pulled pretty decently. Pulling 35g in 30s from a 15.0 g dose resulted in a pleasantly syrupy, raisiny shot. There was no peanut or other underdeveloped character to be found.

Two espresso roasts, 2/18/2015

First roast, stretched out drying as a strategy to improve solubility; 13.53% WL

Second roast, aggressive charge temp as a strategy to improve solubility; <13% WL


And... espresso notes from 2/25/2015, one week post

Again, I pulled these shots seven days out, in a VST 15g basket, ~200F at the grouphead. I used an EK43 this time, dosing 16.0 g and grinding at 1.3. For both roasts, I got 50 +/- 3g in 23-25 seconds. I wanted to extract aggressively to give the slow-start profile a chance at success.
With the slower-start profile, I did really enjoy its profound sweetness and red fruit. However, there was a certain musky, somewhat underdeveloped character, not enough to ruin the shot or enough enough to disturb a pour-over brew, but present.

With the aggressive charge profile, flow was slightly slower. The shot was fuller, riper, more buttery, and completely free of off-flavors (i.e. muskiness, muted peanut-salty-savory character). The shot was slightly less fruited and perhaps slightly less sweet. In any case, my friend and I agreed that the second shot was significantly better.

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TomC (original poster)
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#5: Post by TomC (original poster) »

Brewing notes added. My first batch will likely be ready for espresso over the weekend it was roasted on the 29th, and the odd soapy note is gone, at least in pour over brews. The notes above were on the second batch however, corresponding with the posted profile.

Ehh, couldn't wait so I made some evening capps. This coffee punches hard thru the milk. Very, very intense, rum raisin almost boozy. Tomorrow I'll certainly be exploring a lower dose, finer grind.
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Andy
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#6: Post by Andy »

After 4-day rest I made this in Aeropress this morning. Cherry and tangerine in the fragrance, vanilla and cardamom aroma and sweet red fruit and black tea flavor. Pretty good balance but with slight bitter finish. Not a lot of acidity, which is fine with me.
Modified WP Poppery; [edit-->]150g charge, finish wt. 131g (87.3%):

9Sbeans
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#7: Post by 9Sbeans »

Hello everyone, glad to be here. :)

The 20# package from SM's arrived couple days ago, and I immediately ran two 227-g batches that day after dinner. In retrospect, I don't think the green beans had equilibrated to the room temperature - it was cold (around 20F) outside.

Anyhow, the first batch was charged at around 300F. I wanted to get familiar of the bean, and didn't bother keeping a log. Basically it was similar to my routine 300F charge as shown in this Ethiopia roasting profile (%power & %fan), but I found out that I needed more power. I intended to get to Full City range and dropped at 403F (1st crack + 28F), but realized the weight loss was only 13.91%.



Roasting Info:

Bean: Rwanda Karongi Gitesi
Roaster: KapoK 500 sample roaster
Charge Mass: 227.1 g
Charge Temp: 300F
Dry/Ramp/Development: about 5:05/4:50/3:10
FC-start temp: 375.4F
Finish Temp: 403F
Overall Roast Time: 13:05
Moisture Loss: 13.91%

_____


With the first batch results in mind, I decided to try a higher charge temp (336F) with more aggressive power and fan controls. I didn't reduce the power as the previous batch, and increased the fan before entering into the 1st crack. The decreases of RoR after the 1st crack was still more significant than I expected (notice the drop of BT-RoR @8:30 ~ 9:00). After the 1st crack end, I thought the RoR was very low, and further stretching might be on the verge of stalling and wouldn't get me to my target drop temperature on time. Therefore, I let it run away after the first crack end to hit 407F.



Roasting Info:

Bean: Rwanda Karongi Gitesi
Roaster: KapoK 500 sample roaster
Charge Mass: 227.0 g
Charge Temp: 335.8F
Dry/Ramp/Development: 4:01/3:56/2:46
FC-start temp: 375.4F
Finish Temp: 406.9F
Overall Roast Time: 10:44
Moisture Loss: 14.14%

Tasting results will be updated next week.

---

2/12 Edited:
Although the charge temperature of batch 1 and 2 were different, both batches were aiming for steadily declining RoR. However, both batches had significant slowdown of RoR at the 1st crack. To prevent stalling (further drop of RoR), I let it re-accelerate after the 1st Crack end.

Day 5&6 post-roast, I invited several friends to do a tasting test (by AeroPress. Even though I brought two sets with me, I was still busy keeping my parameters as consistent as possible). When they were asked to point out the preferred cup, I got a close 2 vs. 3 votes of the above two profiles. Longer roasting time (batch #1) has slightly fuller, smoother body, but more people liked the higher charge temperature results, which preserved more fragrance and acidity. When making the morning espresso, both the wife and me noticed and preferred the shorter roasting profiles for its unique & prominent fragrance.

Sometimes I excessively increase the fan speed after the 1st crack end to further stretch the development. In my roaster, the ET could be substantially lower than BT and meanwhile still maintains BT increasing. (the Ethiopian profiles)
Alternatively, I could decrease the power after the 1st crack end to stretch. In this case, I maintain ET higher than BT, and let them slowly converge. I then dropped the beans when ET & BT cross. (the Rwanda profiles).
Given identical BT curves, has anyone compared the tastes differences by 1. Using excessive ventilation to remove heat (ET higher than BT), and 2. With sufficient and constant ventilation, slowly decrease power inputs (ET & BT converge)? I know there are confounding factors, and just curious anyone has compared them before? :?: :)

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TomC (original poster)
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#8: Post by TomC (original poster) »

These espresso shots are like brandy. It's certainly something different. Should be fun to play with in a melange.
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ccr
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#9: Post by ccr »

Just tasting my first two City roasts of this. The first I took too slowly with 5/5/2. This had surprisingly substatial body, clean dark sugar sweetness, and a complex mingling of fruits and aromatic wood. The second I roasted 4.5/4.5/2.2. This still has substantial body, more crisp citrus, and the aromatics really jump out. I agree with TomC's descriptions. I think the flavor and aroma are similar to a mildly aged, fruited liquor.

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#10: Post by 9Sbeans »

I ran two more batches

The batch #3 was aimed to have a linear increasing BT (not S-shaped BT) with constant RoR before 1st crack, or even a slow start/fast finish profile. But it didn't pan out well. (Hence not showing here. :oops: )

Roasting Info:

Bean: Rwanda Karongi Gitesi
Roaster: KapoK 500 sample roaster
Charge Mass: 227.1 g
Charge Temp: 300F
Dry/Ramp/Development: about 5:30/4:40/3:00
FC-start temp: 375.4F
Finish Temp: 410.1F
Overall Roast Time: 13:10
Weight Loss: 14.80%
___

Batch #4, with even more aggressive initial charge temperature. I increased the power at the 1st crack to give it extra push, and subsequently reduced power/gently increased vent.



Roasting Info:

Bean: Rwanda Karongi Gitesi
Roaster: KapoK 500 sample roaster
Charge Mass: 227.0 g
Charge Temp: 354.9F
Dry/Ramp/Development: 3:37/3:37/2:27
FC-start temp: 377.2F
Finish Temp: 410.2F
Overall Roast Time: 9:42
Weight Loss: 14.23%

___

2/18 edited:
The batch #3 was surprisingly good for espresso; the silk-like smooth body and the centered flavors made a very pleasant cup. However, it seems to start losing its origin's flavors. The roasting level was too dark for my liking in AeroPress; I had to reduce the brewing water temperature a little bit. It is very encouraging results, and I decided to experiment more FlatRoR/SSFF roasting profiles.

IMO, applying extra heat during the 1st crack for these beans (the difference between my batch #1&2 and batch #3&4) was very important to keep the momentum and to achieve better development. So far, I still prefer the high charge temperature, Fast Start/Slow Finish profiles (my batch # 4). The dry fragrance and wet aroma were prominent; the exciting sweet, caramel, nutty-like flavors could be identified every time. It needed more rest time to smooth out the minor sharp edges.

___

2/20 edited:
Day 8 & day 9 post roast, all of the stars aligned and the batch #4 (high charge temperature, fast start/slow finish) made wonderful espresso. In addition to the sweet, caramel fragrance, it also developed very creamy and butter-like mouth feel. When the coffee was getting cold, the floral-herbal taste had shown up. It was from the center of the tongue, spreading out, and then going up to the back of the nasal. As already pointed out by NoStream & others, I would consider this herbal taste inherent from the bean, and not from the roast. I planned my roast after reading Tom's & NoStream's early remarks about the unpleasant soapy, medicinal notes, and therefore decided to have at least 2:10 of development time. No sure if longer development time would help to remove the unpleasant taste though. My batch #7 went another extreme, gliding (or, stalling) at the end of the first crack. To be updated next week.

My batch #3 also made good espresso; it made very smooth and focused body. However, in comparison, it was muted and lacked the complexity.

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