Difficult roast

[Sam]

Hi All,

I had a difficult time roasting an Ethiopian Harrar.

I used the Klogic Classic profile starting at 2.8 all the way down to 1.6 but wasn't able to achieve an even roast.

I loaded 100gm of green beans into the chamber and at the end of the roast had about 86 gm out. First crack was about 6:30 minutes.

What variables should I been looking at in this roast and how should I adjust the roast profile to accomodate those variables?

I'm thinking that bean density may be a factor here and the rate of rise of the profile is too steep.The bean weight decreased by 14%. The roast at 1.6 was to achieve a DTR of 25%.

Would a gentler ROR profile work better for this bean?

Thanks in advance.

Sam

[Steve]

Hi Sam,

what kind of end result are you after? what will it be used for?

Being Harrar I am assuming its probably natural / dry process? If this is the case dry process Harrar are well know for uneven appearance.

Your roast never really gets on profile.

I just finished my 8th go at fine tuning a 2019 washed Yirgacheffe, getting it to follow to the Klogic Classic profile. All the early attempts continually floated above the profile curve and upwards into 1st crack. This resulted in less than optimal development (some grass) in the light roast level I want for this bean.

So the final profile has some negative boosts added to reign things in.

I was going to post the profile anyway so may as well put it here, you might want to try it out?
This is for quite light filter roast, cupping and V60. weight loss around 13.5 to 13.75% and 1st crack is still going, feel free to let go for a bit longer if you like.

If you are after a dark even / gentle roast for traditional espresso, give the Steady and Dark profile a go at 4.8. Ive roasted some naturals on this profile and its really really good if you want the old school smooth silky darker espresso roast, pulls amazing ristrettos and I reckon you would end up with dark cherry choc bomb using on the Harrar.

Cheers

ClassicFilter.kpro

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[Sam]

Hi Steve,

I'm looking for a medium roast for espresso and milk coffee. I'm comparing my roasted bean colour with professionally roasted beans from my favourite roasters. Generally, I'm roasting darker than the roasted beans I had been buying previously. I'm trying to get closer to the medium roast from the commercial roasts.

Since posting, I did reach out to my local coffee roaster from whom I buy my green beans. The Harrar of course is dry processed, as you say, and did result in variation in the colour of the bean roast. The variation in my roast was not out of line from what would be expected for Harrar according to my local roaster. My first experience of dry processed beans. I had previously roasted a Brazil Santos which is wet processed and had an even roast with the Classic profile at 2.8. Very different result with the Harrar using the same profile at 2.8.

I did pick up some Yirgacheffe while I was at the roaster, so will see how much variation I get with that.

Thanks for your help.

Sam

[Sam]

Dear All,

The Harrar I've roasted and is very drinkable at day 8 post roast with sweetness and balance as an espresso.

I've attached pics of my roasts using the Classic profile at 2.5, 2.2 and 1.6.

Will be interesting to see how the Harrar develops over the next few days.

So much to learn about coffee and roasting.

Sam

[Steve]

They look pretty good, especially for Harrar. You can pick out the orange under ripe beans. Collect enough so that you can cup 12g ground for filter with 200g water off the boil, steep 4min, then stir 3 times. Wait 10 min and start tasting up to 20 min. Good exercise to see if the taste is worth removing in future?

A lot of natural Ethiopians really benefit from longer resting times to smooth out, so 8 days is not out of the question. The Klogic classic is a pretty solid roast profile overall, I can imagine many people just sticking with that out of the box as it produces pretty good / well developed coffee. Miles ahead of anything you can buy at the supermarket.

[Angela]

Some general observations from the tinkering of a novice roaster:

1. pre-heat recommendation on the Nano, I think, is over-estimated by the algorithm. I get closer initial curve following by dropping pre-heat by 10 to 20% of the recommended value - when I remember.
2. I am unsure if the initial minute or so matters that much?
3. I'm still chasing that elusive Yirgacheffe lighter roast I once found accidentally and lost.
   
   My research, from web forums with roasters publishing Artisan logs, suggests that Ethiopians like:-
   • a long drying phase; that means a slow climb to 160︒C taking ~4 minutes or so
   • a long Maillard phase again around ~4 minutes
   • a short development time - no longer than 1.5 minutes on an under 10 minute roast- -
   • lower DTR, so let it go hang on Ethiopian beans - aim for 10︒C over FC temperature

For Yirgacheffe, I use it with a French Press for the first three days and then leave it to rest until day 7 or longer and then mainly use it blended in espresso.

Appended is one log from a series of attempts with Yirgacheffe. It was better than others in the series but more is still to be had; I suspect the temperature rise, off profile, and earlier than planned end to the roast probably helped. But you can see where I'm playing.

[Sam]

Hi Angela,

Thank you for the profile. I do have some Yirgacheffe greens waiting for my next roast.

Good to know that I'm not alone being challenged by Ethiopians. Definitely lessons to be learnt from difficult roasts.

What do you do with your "less than satisfactory" roasts. I don't like binning beans even though my roasts are only 100gm batches. I'm using up the Harrar as espresso. I'll also give Steve's suggestion of a filter a go.

Sam

[BenN]

Following this thread as I also find bit of challenging with Yirgacheffe.
It's my all time fav variety and recently chance to get green.
I have done with my own for lower level get reasonably good result but I think there is more potential.

And Thanks for Angela, very interesting to what you are doing with your profile.

[Angela]

....
What do you do with your "less than satisfactory" roasts. I don't like binning beans even though my roasts are only 100gm batches. ....

Sam, my earlier reply got lost in the kerfuffle of ISP change. To briefly re-cap; I keep everything and blend poor quality roasts with other left-overs. I keep them all in an Airscape.

Sometimes it works well and sometimes - well... Still what I drink from those blends is probably no worse than supermarket coffee beans.

[Sam]

Hi Angela,

I'm with you. I don't like to waste beans.

I'm slowly making my was through the Harrar I roasted earlier. I was surprised how well the Harrar performed as an espresso between Classic levels 2.2 and 2.8. Very drinkable both as an espresso and with milk. I'm not getting as much complexity with the Harrar at 1.6. I think I will try blending it.

Sam