Maybe I'm reading your graph wrong, but it looks to me as if you dropped a few seconds before the point marked on your graph; the temperature is falling a bit before the point marked drop, which is where it measured 413C. So I wonder if your actual finish was hotter?

In any event, thanks for sharing these interesting notes and results. It is surprising to me that you noticed a lot of body despite stopping so soon after FC. I did two minutes of development and still noticed a fairly light body in my initial roast.

I'm also surprised to hear that you are getting funkiness, as mine has been very clean. Do post again to let us know if that goes away as it ages!

Hey Mark,

I think the fact that it looks like I dropped earlier is an artifact of Artisan plotting, because when I look at the raw data, my drop temperature was indeed the hottest BT I saw.

Your comments around the coffee body make me worry that I mixed up my samples -- I carried 4 unlabeled mason jars into my kitchen at one point and was fairly sure I didn't mix them up, but in he back of my mind I thought it was a possibility. I guess I'll find out in the next few days when I try them as espresso!

Funkiness wasn't bad, and I wonder if it could be because of differing roast levels. So hard to compare between two people remotely, since i doubt our thermocouples agree, especially considering our respective first-crack temperatures...

frank

As a follow-up to impressions of the roast profile I posted a couple days ago, today marked 5-days post roast so I had a chance to try it as espresso. The shot was extremely sweet and mild fruity (more like stone fruit than blueberries). Chocolate overtones were still strong, but as espresso I didn't mind as much. Acidity was prominent without being overwhelming, more malic than citric.

I still think that by going lighter I can coax out more nuance without underdevelopment, but as far as this roast goes I definitely prefer espresso vs. aeropress.

BTW, sorry for my horrible taste descriptors. It's not just a function of my lack of vocabulary, but also I think my palate is probably pretty underdeveloped too.

frank

Can you guys explain more about what you mean by finish temp. I do not have a true roaster but am learning about the process and just doing a simple stovetop at home. I always thought first crack would run until like 426, and second crack around 454, but then discovered that was a thermoprobe reading. You guys are dropping at 421 and 416, but how do you know the internal bean temperature? Do you just have a thermometer in the bean mass, or is it some other way?

Also, if I can ask, what exactly do you mean by dropping? I assume just removing the beans from heat, but dont want to make a faulty assumption.

In a commercial-style drum roaster, you end the roast by opening a gate, so that the beans fall out of the rotating drum into a cooling tray. Thus, you "drop" the beans.

As to finish temperatures, it is dangerous to read to much into these unless you realize that temperatures can vary greatly depending on where you measure in a machine and how responsive your thermometers are. When I used to roast in a heat gun/bread machine set-up, I would measure first crack around 390F; now, in my drum roaster, I typically get first cracks at a measured temperature of 375F or so. These measures are always approximations of the true average bean temperature in the system, and should be treated as such. One thing that is helpful when trying to translate someone else's profile so that you can imitate it on different equipment is to compare the temperature at which first crack began with the finish temperature. "Add 20F to the beans over 2 minutes after the onset of first cracks" is more likely to be comparable across different roasters and measurement setups than is "drop at 425F."

So here are the profile and initial tasting notes from a roast that was intended primarily for espresso consumption:

---

Roasting Info:

Bean: Ethiopia Gedeo Worka FTO - DP
Roaster: USRC Sample Roaster
Charge Mass: 400 g
Charge Temp: 300F
Dry/Ramp/Development: 5/3:45/3:30
FC-start temp: 378F
Finish Temp: 405F
Overall Roast Time: 12:23
Moisture Loss: 16%

Profile Plot:



[BT=Red, Exhaust=Green, Gas=Blue, Fan=Yellow]

Tasting Notes: I pulled my first shots of this coffee with three days rest, on my Caferina, which is very similar in design to an early, first-generation Pavoni Europiccola. The grind was a bit finer than usual, and the pull a bit hotter, than my typical starting point, as I kept this roast a bit lighter to preserve the fruits I enjoyed in the brewed cup. I ground 16g and pulled a 28g shot, for a brew ratio of 0.6. The pull was slow and hard, using fairly constant pressure to produce a pump-style shot, and produced a shot with a nice, thick crema with some nice mottling on top.

Upon tasting, this was an excellent shot. The acidity was less blueberry-like, and reminded me more of sweet blackberries and peaches. There was a rich, bittersweet chocolate flavor, which lingered well into the aftertaste. There were also aromatic notes of marzipan, saffron, and even a bit of lilac. The body was thick and syrupy. If I had been served this without knowing what coffee was used, I would probably have guessed that it was a blend, given the nice balance between high and low notes.

I'll probably try this as a brewed coffee tomorrow, just to see how it fares in that preparation, and I'll let you all know the results.

Blackberries and peaches! One of my favorite summertime combinations. Alas, I am forced to enjoy this coffee vicariously as my house is torn up in part to prepare a coffee nook off of the kitchen. I can't get to my roaster in the basement and at 0 degrees Fahrenheit it's too cold to roast outside. But, I am enjoying all of the R&L experiences.

Roaster - Hottop B-2K with variac and TC4C

I targeted a drop at 1:45 after start of first crack, or temp of 1C+27 F. The roast accelerated near the end, so I dropped at 1:30. Based on preliminary tasting, I should have gritted my teeth and roasted to 1:45.
NOTE - my thermocouples read 30 degrees lower than most others. As noted in this post at Sweet Maria's, I have virtually identical readings as Barrie. We both have identical Omega probes installed in the same location on our Hottops.



Evaluation
Had a pour-over of this coffee after three days rest - not as good as I expected. Due to the very fast roast, it was a bit underdeveloped.

EDIT - After two more days rest, I had a vac pot of this coffee. Additional rest was definitely an improvement.

I've roasted four roasts with the Gedeo Worka (FYI, Gedeo is in Yirgacheffe, and Worka is a co-op comprised of a couple hundred small scale growers), so far. My impressions of the C/C+ roasts, brewed balance-beam siphon were not terribly different from those of most of you contributing to this thread. Mostly, as they say, this bean is "the berries."

The Worka is very similar to some 90+ Jinbar (also from the Yirgacheffe region) I got from Boldjava. Brewed, the Worka has a similar berry presence, a little less sweetness, more (baker's) chocolate, more stone fruit, and better mouthfeel.

The Jinbar made excellent espresso.

I took a couple of my early Worka roasts to the border of FC. Roast 1, Dropped at 428F, to get a feel for roast milestone temps (although I cheaped out and didn't go all the way to 2dCs); and Roast 2, with espresso specifically in mind. Both roasts went into the espresso grinder on the 11th.

January R&L 2: JGR ("Jolly Green Roaster," a USRC 1lb Sample Roaster)
Charge: 400g
Drop: 338g
Level: C+/FC



To be honest, I was distracted at the very end of the roast for a few seconds and went past my target Drop temp of 425F. Also, with this as with all of my Worka roasts, 1stCe is indistinct.

The roasts were still a little fresh on the 11th, but were fully rested five days post roast. As of eleven days post roast, the roasts are still in their "best" window... but it's closing.

Ground for espresso the aroma is very close to the in the cup results for brew. When pulled slightly cool -- (estimating) 198F - 200F as best temp range -- the espresso has plenty of baker's chocolate, cardamom spice, some vanilla, good sweetness, cherries, but lacks most of the berries and fruit suggested by the aroma; pulled cooler, the taste moves to sour without any additional fruit. Mouthfeel is silky, with good weight; excellent for an Ethiopian.

There's better espresso in this bean than I've been getting. In my next espresso roasts (today), I plan to shorten the drying period and lengthen the ramp and to Drop at a slightly lower temperature -- 423F -- while retaining a 20% Development, with a target profile of 5:30, 4:30, 2:30. Whether or not that's doable is problematic, 2:30 Development to 423F won't be easy without stalling.

No score until the profile is nailed.

This is a nearly perfect R&L coffee because there's so much in the bean but the best profiles aren't immediately obvious. Guys, please keep posting. I'm learning from every roast you do.

Rich

boar_d_laze wrote:Also, with this as with all of my Worka roasts, 1stCe is indistinct.

Schooley recommends, for DP coffees in this article http://www.coffeeshrub.com/shrub/conten ... ed-coffees, pushing a little harder right into 1C to overcome this lack of distinction. I've found it quite helpful but requiring serious brakes once 1C gets going to avoid it getting away.