Raost

[benjaminfleon]

Hey everybody! First time posting here. I've been roasting on the Kaffelogic for a couple of months and been a member of the forum for about a week.

I've been having great results with this particular profile, works great for medium to high density washed coffees; the one I'm roasting right now is an Ethiopia from Sidamo provided by MareTerra. I'm uploading two versions: the "original" and the one I optimized for this particular coffee.

Raost.kpro

(2.15 KiB) Downloaded 748 times

Raost Sidamo.kpro

(2.33 KiB) Downloaded 616 times

This profile is basically me trying to apply the concepts from Scott Rao's books on roasting as simply as possible (hence the name). Ideally, use it for 100.0 gram batches. The best results for my particular palate (bright, juicy, sweet coffee with lots of clarity and balance at high extractions, but not a lot of texture) were between 1.6 and 1.7, but feel free to try other levels.

FC is around the 5 min mark, and you get about 27% DTR at 1.7 (219.9 ºC).

Also, I might add that I've been experimenting with the method for rehydrating coffee proposed by Christopher Feran in his blog <https://christopherferan.com/2021/03/15 ... -protocol/>.

1.png (103.32 KiB) Viewed 13241 times

2.png (92.12 KiB) Viewed 13241 times

The first picture is a log from the coffee I mentioned at 11.7% moisture, and the second is at 16%. The rehydrated coffee was brighter and sweeter. This is particularly useful if you happen to be roasting coffee that's from an old crop, or hasn't aged beautifully. As you can see, and as Christopher points out, the rehydrated batch uses more power throughout the roast, so I recommend using his calculator to arrive at the same batch size so it's not as different (he posted it in the article, so you can make a copy on Google Sheets and use it).

I've been working on a couple of other profiles too, I'll post them soon!

[Barry O'Speedwagon]

Welcome. Looks interesting. How are you brewing your coffee? Filter / pourover?

[benjaminfleon]

Hey Barry,

I'm pulling it as espresso and also brewing on pour over. I tend to enjoy the same roast on both.

For espresso, I'm currently doing a 1:3 ratio between 15-20 seconds at 6 bar pump pressure, aiming for 7-8% TDS*. [This setting allows me to pull Allongés without changing grind size, and just going for a higher ratio (1:5 - 1:6)].

*For a more traditional 1:2 espresso between 25-35 seconds at 9 bar, I'd probably develop a little more, 1.8 would be a good start I guess.

For filter, I'm usually between a 1:20 - 1:22 ratio, aiming for 1.35-1.45% TDS. I've been using the Tricolate and also V60 with Kalita Wave filters. Boiling water, and trying to keep bypass and channeling at a minimum (several pulses and gentle swirling after each pour). Total time is usually between 4-5 min in the V60/Kalita Filter; 7-9 min in the Tricolate.

Also, just in case it's useful information for you:

I use both my own water recipe, on the harder side (185 ppm of magnesium sulphate for hardness, 38 ppm of sodium bicarbonate as buffer) for pourover; and filtered water at the café I manage (which is usually between 15-25 TDS, mostly made up of CaCO3) for espresso. I've made my own water a couple of times for espresso too; basically adding more buffer to my recipe (185 ppm hardness, 50 ppm buffer).

[Barry O'Speedwagon]

Interesting thanks. Intutively the 1.6-1.7 roast depth seems too light for espresso for my tastes....but....I perpetually forget that the roast depth score is not measured on anything like a ratio scale (i.e. 2.0 is not twice as dark as 1.0). I have a Cremina it's not a problem extracting at low pressure. Might give it a go sometime. I've also got a V60 banging around somewhere

[mr. bean]

Looks interesting Benjamin.
Can you explain more how and why you optimized it for the Sidamo?

[benjaminfleon]

Sure!

There are a few differences on the Sidamo profile*, which you can actually check on if you compare both files on Studio:
— There's a boost of 2.5 between 3:05 and 3:55
— There's a boost of -2 between 4:45 and 5:30
— There's a power profiling zone of -3.8 between 5:00 and 7:30

I found that this coffee in particular wasn't following the curve perfectly at those times and just tweaked a little with it; but didn't change the profile or the fan setting, so I decided to keep the original as a starting point.

*Also, in an updated version of Raost Sidamo, from a few days ago, I changed the "roast end by time ratio" setting from the 0.33333 default to 0.9, since I wanted time to be prioritized by the machine as a ending point. Here's the profile if you want to download the updated version, but you can just change that setting and it'll be the same:

Raost Sidamo.kpro

(2.33 KiB) Downloaded 522 times

[mr. bean]

I've tried the original Raost with a couple of washed beans: Australian Dimbulah Estate, Kenya Lena AA and Peru Kontiki. I cupped the Australian and the Kenyan today (2 days old), and I liked them. No noticeable defects (to my untrained palate!), and a good amount of fruit and sweetness.
The Australian is from Athetern Tablelands (north Qld) and whilst relatively low altitude is quite a dense, highly washed bean. It seems to handle fast, hot roasts fairly well. One positive of this profile is that it actually achieves a noticeable 1st C on the Australian, which is often barely perceptible...

I haven't tasted the Peru yet, but it's a lower quality bean, and I can see some tipping on the beans and as you can see from the profile, it seems to have gone a little haywire...

log0727 - Aus, Raost.png (66.96 KiB) Viewed 13105 times

log0728 - Kenya, Raost.png (66.78 KiB) Viewed 13105 times

log0729 - Peru Kontiki, Raost.png (71.55 KiB) Viewed 13105 times

Based on the way the Kenyan seemed to run a little high from 4mins, I modified it to have a -3 boost from 4-5:30mins. I used this on the Australian and the Kenyan again...

log0731 - Aus, Raost (-3 boost).png (68.4 KiB) Viewed 13105 times

log0733 kenya, roast (-3 boost).png (70.34 KiB) Viewed 13105 times

I think it needs a negative boost all the way to the end though from the look of it...
And perhaps the Australian would respond better to your 'Sidamo' modification looking and where it creeps up and down...

I've also created a mod with -6 power profile from 5-7mins to try with the Kenyan to see if that improves the stability of the last section... haven't used it yet though.

One more thing. A repeat roast of the -3 boost mod on the Australian seemed to create a very pronounced Crash and Flick around 1st crack. Not sure why it was so pronounced in the second roast which was identical to the one before it...

log0732 - Aus, Raost (-3 boost).png (68.69 KiB) Viewed 13105 times

Any thoughts??

[benjaminfleon]

Hey!

I'm glad you've enjoyed the coffee you're getting with the profile; I'd say keep experimenting to suit the way your coffee is reacting, and maybe try different end temps to your roast level preference.

I've also noticed that FC is easier to identify; I suspect proper build up of energy and pressure at the start of the curve may contribute to this. I'm still short on data to be sure though.

I think you should be able to reduce some tipping by rehydrating, I hope you try it. Also, the peruvian coffee might benefit from power profiling to smooth out the power curve. Let me know what you find when you taste it.

Regarding the mods, I agree that maybe the Sidamo version would be a better fit for the australian coffee; and definitely try the -6 power profile, I think it might do the trick too. However, I would extend it through the 7 min —maybe to 7:30—, otherwise you might a experience a bump in the end power like the one you see in #0733.

As for the crash and flick on the second aus roast with the -3 boost, I think you might have some issues with your power supply, or maybe a change in ambient temperature is playing a role here; and the PID might be overreacting to it. If you look at the power curve in both logs (#0731 and #0732), you can see a dip on the second one around the 5 min mark that isn't there in the first one. Maybe someone else can provide more insight on the issue.

Anyways, thanks a lot for the feedback!

[mr. bean]

I took a look at the rehydration article...
Do you have a moisture meter? Or are you just assuming you want to increase by around 4%?
Had a quick look online and coffee moisture meters are expensive! Although would be handy. And I actually happen to have a coffee tree in the backyard and harvest over a kilo of coffee, and have always just had to guess at the dryness levels... tempting...

[mr. bean]

Btw, did some some aeropress ‘cuppings’ today of the 3 Raost roasts and also put in a Colombian roasted with Firestarter as a comparison. I definitely think the Roast worked well with the Australian and the Kenya. Good, pleasant acidity and sweetness. The Peru was ok, and better than the Firestarter Colombian, which had a slightly flatter, more roasty flavor. It was a darker roast, so probably not fair comparison though...