Roast and Learn Together - February 2015 - Page 3

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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TomC (original poster)
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#21: Post by TomC (original poster) »

9Sbeans wrote:Any luck with the melange? :)

I used to blend 10~14-days rest, lighter roasted beans with 6~10-days rest, darker roasted beans to make espresso. I have tried cross-blending my earlier lighter roasted Rwanda with the later, darker roasted ones. The results were good, but not exciting. I feel it lacks a "central scene", be it fruits, body, or chocolate. It's a well-rounded cup, but I haven't found out the focus to be emphasized.

I must apologize, I'm falling a bit behind this month. With several coffee reviews, and dialing a new espresso machine separately,as well as redesigning the layout of my kitchen, I haven't put as much time behind the tryer as I'd like.
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TomC (original poster)
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#22: Post by TomC (original poster) »

Three batches ran last night, including one that was purposely the darkest, most developed roast I've done in years. The more complex dry distillate aromatics suddenly bloomed in the roaster for that particular batch and was a good point to end it. I'll throw up some graphs later on as I evaluate them individually.

I'm pushing a different strategy with this green, really really trying to stretch the ramp thru the maillard as long as I can, without overshooting my total post crack temp rise. Hotter charges and tweaks to the airflow have enabled some fun experimentation. I'd like to see this coffee's maillard complexity stretched to it's absolute limit without being roasty.
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TomC (original poster)
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#23: Post by TomC (original poster) »



Brewed up yesterday and again demonstrated today, this coffee really likes a darker roast than what I normally ever do, especially for drip. I've never taken a coffee thru 16.3% weight loss intentionally if it was going to be brewed as drip. But an interesting thing happened during the brew. I was inspired by watching all of the USCC stream, so I broke out my Cona, BOS brew board, the works (the pretty stuff saved for guests). At first I thought it might have been a one-off fluke, but when I stirred the bloom (Cona's tend to brew much cooler than Yama's and benefit from more agitation) the bloom released a very powerful, clear aroma of vanilla extract. The cup was stellar. It did the same thing today with the vanilla effect. The aromatics of this coffee are wonderful, deep and complex.

On the roast, all batches were 250 grams. This one, the third in the session I intentionally pushed quite hard throughout the roast. I love roasting, but I was actually grinning ear to ear taking a coffee this close to 2Cs. I'm not as detailed in my roasting recording as some of you, I don't log the power changes, the fan or the MET, but my various profiles I ran were aimed at the same general approach as mentioned previously, charge hotter, develop the Maillard phase slowly and extended thru the ramp, then vary the finish level of development and see what I get.

The profile above I'd say was quite better than this next one. In the roaster, the #3 profile's distillate aromatic change happened quickly, and smelled incredible. The cup brewed up without harshness or bitter tones. It was complex, sweet and unmuddled. Early to say, but you can see it's a short roast with a lot of power, I think the shortness of the roast helped retain some of the brightness, even at this extreme level of development. This will be the coffee I'll test first as espresso.




Profile # 2 was very similar, hot charge, stretched ramp, but overall, gentler in speed throughout, ending in a longer overall roast time. Same batch size of course. I just finished sipping thru this batch for the first time and find it to be more of a comfort food crowd pleaser. It's smoother, with a praline sweetness, yet less bright. I prefer the #3 roast by far.

I'd highly recommend folks try this coffee in a well developed full city range. It's complexity only compounds and improves. I don't have any soapy, off notes or detractors in the cup.
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TomC (original poster)
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#24: Post by TomC (original poster) »

Ehhh, ultimately, I think this coffee does far better as brewed vs espresso. My espresso roasts were far from nailed down. They were sweet, bright, yet too complex on the palate for me to really enjoy. I had a lot of tobacco mixed in with the raisiny brandy notes in most of the shots, so the remainder of the coffee will be fiddled with as a brewed coffee, or maybe a minor component of a blend.

It was a short month. I also dropped the ball a bit being busier with other coffee projects. It's tricky to figure out a green coffee that is widely available, well described by the vendor, and generally popular without being somewhat redundant. Then get enough various profiles on it that something concrete comes out of it, but I hope the sharing process here is of value to some.
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Boldjava
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#25: Post by Boldjava »

TomC wrote:...

It was a short month. I also dropped the ball a bit being busier with other coffee projects. It's tricky to figure out a green coffee that is widely available, well described by the vendor, and generally popular without being somewhat redundant. Then get enough various profiles on it that something concrete comes out of it, but I hope the sharing process here is of value to some.
Tom - you are being too self-critical. There is no "pure" learning experience. Everything comes in spurts in life. I have learned something with every coffee I have done within the Roast and Learn efforts.
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[creative nickname]

#26: Post by [creative nickname] »

TomC wrote:Ehhh, ultimately, I think this coffee does far better as brewed vs espresso. My espresso roasts were far from nailed down. They were sweet, bright, yet too complex on the palate for me to really enjoy. I had a lot of tobacco mixed in with the raisiny brandy notes in most of the shots, so the remainder of the coffee will be fiddled with as a brewed coffee, or maybe a minor component of a blend.
That's interesting, as I ended up liking it best as espresso! My best shots have all used a fairly light roast, and were pulled on my MCAL. The results were rich, complex, and nicely balanced. I think this coffee has so much body that it can be overwhelming if you pull a concentrated shot using high pressure or darker roasts, and in fact, my very favorite shots were all fairly long singles. Have you played around at all with any lower pressure shots using a lighter roast?
TomC wrote:It was a short month. I also dropped the ball a bit being busier with other coffee projects. It's tricky to figure out a green coffee that is widely available, well described by the vendor, and generally popular without being somewhat redundant. Then get enough various profiles on it that something concrete comes out of it, but I hope the sharing process here is of value to some.
You are being too hard on yourself! This was a great choice for a coffee, and I definitely feel like I learned a thing or two as I tried to adapt my roasting and brewing techniques to deal with a coffee that had this unusual savory character.
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9Sbeans

#27: Post by 9Sbeans »

I still have 3 more batches of Rwanda greens. One more profile to try in my mind, is the "charge at lower temperature, so that it can finish at a higher temperature" Rao's style profiles. I have practiced this style on other beans, and will give it a try on these Rwanda in coming months. Will update here.

I haven't touched Rwanda for years. Most of my beans are from Ethiopia, Kenya, and Centrals. I appreciate this opportunity to experience, to learn, and to have a lot of fun. :D

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

9Sbeans wrote:I still have 3 more batches of Rwanda greens. One more profile to try in my mind, is the "charge at lower temperature, so that it can finish at a higher temperature" Rao's style profiles.

Just curious what you mean by this? Rao's principles are to always be removing heat from the system, not going from lower to higher at the end.
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9Sbeans

#29: Post by 9Sbeans »

TomC wrote:Just curious what you mean by this? Rao's principles are to always be removing heat from the system, not going from lower to higher at the end.
It's in one of Scott's comments below this article:
Guest comment: Development-time ratio by Scott Rao
scott Rao says:
June 3, 2014 at 6:53 pm
Kenny,
It can be done; it may involve charging cooler or using less gas in the first half of your roast, or perhaps other adjustments, like entering first crack with a lot more momentum. But the ratio should still apply, even at a darker roast like yours.


One of the examples is in Jang's roasting profiles:


It has been pointed out (somewhere in HB) that the BT probes in those Giesens during the contest were heavily filtered/smooth-out and have lost valuable information. In addition, the gas/fan adjustments were not logged in the file.
In Jang's roast, we can see the skewed BT still shows the S-shape, declining RoR feature. More importantly, we can see the ET jumps twice and decline once during the roast (highlighted in red & blue arrows). It can be seen in the deltaET plot, two peaks and one dip. IMO, these reflect the timing of the gas adjustments: Jang increased gas at the turning point and the end of Drying, and he reduced the gas when entering the first crack.

It is possible to increase power input while maintaining steadily decreasing RoR.



This is one of my practice roasts with old crop (I didn't go into the 2nd crack).
In my settings, the drum has vast thermo mass (heat capacity) to dictate the BT profile for the first 3 mins. After the rebound, the temperature difference between the drum and beans reduces, hence always declining RoR. If I charge at a slightly lower temperature, I can increase from 28%-power to 32%-power at 4min, and still keep the RoR checked. The lower charge temperature compensates the higher power in early phases, and we can reach the first crack at a reasonable time frame. Because it has higher power (stronger momentum) while entering the first crack, it can reach a higher drop temperature within the same time period to fulfill the 20-25% ratio.

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NoStream

#30: Post by NoStream »

I bought a 5 lb. bag of this and have been executing additional profiles, so I'd like to revive this thread a little bit. I've been experimenting with some fast Rao profiles, starting with high power, hot drum, and trying to only reduce power to as much as possible.

Here are the first two exploratory profiles.

This is a variation on my previous baseline. Charge hot, bounce with primarily drum energy, lots of power into ramp, slightly increased air later in the roast, Rao-approved development phase.



Now here's something closer to a true Rao roast. No fan adjustments. High power at first but also in ramp.



I evaluated these at 20:330, 7.0 EK, 202 F V60s. The first was dramatically brighter, more aggressive, and more fruited. The second, much smoother, more chocolaty.

And yesterday, I executed two more, really try to push the roast through quickly, stick to strictly declining heat application. This inspiration here is the current March Roast and Learn Together thread. Of course, I don't expect such an approach to work quite as well with this bean, but we'll see.

Here's the first, starting at 7.5 amps out of 10 possible.



And here's an even more aggressive one, starting out at a full 10 amps, just to see how far I could push this. You'll see oscillations in the graph that I believe are just noise, as I have my smoothing settings quite low.



Initial results this morning were promising, but I won't post full notes until I'm a few days out from roast and have had others taste as well.