Raost

[nsolling]

Hi, I did a few roasts with the v4 profile.
I can see that dose is extremely important and you should not load more then 100g at a time - changing dose is an unnecessary parameter to change.
With 120g I found the roast not to follow the roast curve too nicely - Strangely enough I logged FC earlier at higher dose (Like 10 seconds earlier) and at a lower temp - Don't know how I can quite explain that (less agitation of the beans due to higher weight?)
With 100g dose it seems quite reliable though.
Could also be that I recorded FC wrong - Those beans are quite silent when they crack.

It is a quick roast with quite a high DTR due to the short time to FC, but I think the results seems good - Now waiting for them to rest a bit.

For those interested:
- 1.7 dev came out at Agtron 82 (Med-light)
- 1.9 dev came out at Agtron 76 (Medium)

I did 3 batches back to back roast of each dev level: 120g, 110g and 100g and did get slightly different results on the roast curve.
At higher dose the temp. development seemed to be quicker or higher.

Next time for persistence and accuracy I will use 100G only.

Bean is a Guji Kercha Ethiopian 1900 - 2200M

Attaching logs for those interrested:
53: 110g - 94g out
54: 120g - 100g out
55: 100g - 86g out

[nrdlnd]

Thanks for sharing!

I only looked at the 100g (log0053). It looks nice. I see that the profile has a flat power zone between 4:35 and 5:40. (Zone 1). It is possible to straighten the ROR curve between 2:45 and 4:10 with a negative boost. I don't know the amount maybe around -3. You have to call this the zone 1 then and the power zone 2. This will probably make the first crack come later and the whole roast a little longer depending on the development time and end temperature. I don't know what difference this makes to the taste of the roast though.

Before I have made a roast with V4 and 95g washed Sidamo Vendo. I stopped at L=1.5 and end temp 219.1. The log looks different compared to your (different beans!). It was OK but not more. In my notes I have written that some beens looked burned. I did not go on with this profile. Your log looks better. I got better result with another variant of the Raost profiles (Slow Raost).

Interesting that you can measure Agtron! How do you do that?

[nsolling]

Hey. I use a roast meter from espressovision.com.
It is the most cost effektive roast meter I have come across and so far very consistent.
It does not measure direct in agtron, bur there is a conversion chart om their site.
I am in no way affiliated with them, but I do believe the product is good and I found a discount voucher on their website.

[nrdlnd]

It looks good. Especially at the lighter roasts it is difficult to distinguish between different roast degrees and that is where it's most important. We need to have the same language. What is light for one person is medium for another person. This device is rather expensive and they only sell to the US (I'm in Europe). I have downloaded some charts but you can never be sure that the colors are correct when something is downloaded from the net.

Roasts that I've called "light" is probably most often medium-light or maybe even medium. I think that to produce a color correct chart shouldn't be too expensive but I don't know where to find such charts. There is also a lot of different scales. Agtron is some kind of standard and is correlated to lab measurements. "Nordic" is supposed to be light but the coffee we drink here in the Nordic countries are medium or darker not light as sometime is said. The scale light-medium light-medium-... etc. I think is useful when it's correlated to an Agtron value. It says something about the color of the coffe. Scales such as City-Full City-...etc is nonsense in my opinion.

[Damian]

colour meters are not that useful either, as a rough guide maybe, but really no better than by eye.
You can roast to the same colour different ways, different depth of roast, with very different taste results.

For example, here I show 2 curves, where I have only changed post FC stage to produce two different results which will show exactly the same to a colour meter.

1.jpeg (45.91 KiB) Viewed 7826 times

[nrdlnd]

Yes I agree. But there is still a problem that we don't talk the same language. I guess these two roasts have different developing times. The one that ended earlier but at a higher temperature was it lighter inside? Can you tell anything anything about the difference in taste between those two roasts?

[nrdlnd]

I have worked a little with Raost V4 but I have said before that I didn't want to go on with that profile. One of the reasons was that I think it gave an uneven roast and some beans looked scorched and they had a tendency to be lighter inside. I don't know the reason for that but I tried to make the ROR curve more even and I raised the preheat. I made two roasts with different settings and I show the second that looks the best (less scorched and more evenly roasted and straighter ROR curve). The original V4 Has a power zone with boost 0 between 4:35-5:40 and a negative boost zone between 5:40-6:00.

I changed this to a boost zone -3 between 3:00-4:21. Changed the 0 power zone to between 4:35-5:15 and a new -3 boost zone between 5:15-8:00. The roast is not meant to go that long but I wanted to have a margin. I don't recommend higher L than 2.1. I raised the preheat to 1000W. I don't think I got the roast levels right but you can ignore that. It's only arbitrary anyway.

I made a roast with 95g of a washed Sidamo Bio. L became 1.4 with an end temp 218 and a DTR 27%. The roast looks to be Light/Medium Light. It is maybe possible to lessen the negative boost at the end to for example -2 instead of -3. This roast looks more evenly roasted than my earlier roast with the Raost V4. I can't explain why but it could be the higher preheat combined with the more straight ROR curve.

I publish a picture of the log and the modified profile. I haven't tasted the roast yet but I can edit that later.

210826_2_SidamoBio_RaostV4PNmod_1.4.png (65.44 KiB) Viewed 7794 times

RaostV4PNmod.kpro

(2.25 KiB) Downloaded 315 times

Edit: Taste after 10 hours rest brewed with V60 the 4:6 method by Tetsu-Kasuya. It was a course grind more like French press with a flat burr grinder: First impression was a not unpleasant acidity (malic acid?). This acidity went away after a while. It was a rather complex taste and rather balanced. Some body and a long aftertaste. I think the roast needs more rest. I don't quite know what this bean can give. I made a roast a day before with the bean with another profile but my machine hadn't quite the voltage for that profile. The roast above was much better and I did enjoy the coffee.
Edit: Taste as espresso after 46 hours rest: First impression is that it's creamy. It has a lingering acidity that's actually pleasing more like citrus. Not so much body. Froutiness as aftertaste. A rather special but nice espresso!

[TheBean]

Hey @nrdlnd !

Thanks for your post, I was about to post about that! Regarding the D-Raost profile, I actually just tried it and came across the same problem some people were having with the original D-Roast (i.e: not enough power, and having to adjust the fan speed to avoid a stall). I had only tried it before with a super fermenty anaerobic processed coffee that took heat incredibly fast, so I didn't notice the issue.

My usual voltage is in the 218-225 range, so I adjusted the profile to work better for that scenario. I'd recommend going with the first version for higher voltage. Here's v2:


D-Raost v2.kpro


Here's a comparison of both versions. 80 gram batches of the same coffee (washed ethiopian between 1800-2000 masl), V2 over V1 (225-226 voltage).


D-Raost v1 v2.pngD-Raost v1 v2 fan.png


V2 isn't perfect, but I think it's a better starting point for those who have lower voltages. For this case, I'd either lower the preheat power for the 80 gram batch, or roast larger batches; as well as apply a couple of short boosts. In any case, every coffee will be slightly different, so with a few tweaks I think you can get it in really good shape.

You say that you name your profile after Scott Rao and you refer to his book "Coffe Roasting: Best Practices". I do only have his former book "The Coffee Roasters Companion" but I may get the book you mention. In the book I have he mentions that a DTR between 20-25% is to strive for as he had noticed that gave the best taste among the roasts that he had tasted. Your profiles are either below or in most cases above that range. Doesn't Scott Rao put any importance to this development range any more?

I understand that Scott Rao recommended 20-25% as a rule of thumb for most roasters, and not really thinking about specialty coffee. He's posted and said a few times recently that he does not recommend to give DTR a huge importance as an indicator of when to drop a batch (or end a roast in our case), and puts a lot more importance a steady decline in RoR, on end temperature and color. Instead, we should take DTR as an indicator of "a balanced curve".

I've found that I've gotten more sweetness in the 27-30% range at the speeds and temperatures I often roast, so I go with that instead.

Your end temperature 219,9 deg C is rather low and I think means a roast on the light side. Are the beans evenly developed? If you cut a bean does it have an even color inside?

About the end temp, 219.9ºC is usually my lowest end temp (unless, again, I'm roasting something super heavy on the processing, which I roast as low at up to 214). Uneven development at those temperatures hasn't really been an issue for me. I don't cut the beans as often as I maybe should, but when I have it's been a pretty even color. Without a color meter I couldn't say whats my variance between inside and surface for sure, though. (Also, it's often hard to talk about what's "lighter" or "darker" without also talking about extraction yields)

The Sidamo profile was used for a fully washed process; but given what you've said, I think I'd recommend you try the Slow Raost profile first. It's pretty good compromise between texture and flavor balance.

Hi @benjaminfleon, I’ve tried yours D-Raost V2 and whilst I have the same voltage as yours, I still received the “low voltage” message - is it normal? Cheers.

[Damian]

Yes I agree. But there is still a problem that we don't talk the same language. I guess these two roasts have different developing times. The one that ended earlier but at a higher temperature was it lighter inside? Can you tell anything anything about the difference in taste between those two roasts?

Colour is the same, whole bean or ground.
The shorter faster development will be more acidic wine like, less sweet, the other sweeter nuttier

I agree, there is no unison with roast interpretations, but colour isn’t the answer IMO
The best way to advise roasts would be to include roast curves with them

[nrdlnd]

Hi The Bean,

Damians D-profiles are very good but require a high voltage supply. I have tried the D-Light with good results when Iv'e had enough voltage even if it has been near the limits but some times not and with lesser result. I think the D-Raost is built on the D-profiles.