Colombia Melky Chevaz - What works for you?

[Beanz]

I'm having trouble zeroing in on the best K-Profile to use for this bean and wonder what you might have found works for you. I guess that is one of the points of this forum?

I have tried K-Classic at 4.0, 3.7 and found it burnt to my taste. Dark chocolatey rich and smooth otherwise. I have since tried Firestarter 3.3 and it seems to have changed character altogether. Astringent with ashy aftertaste....

One of the things not helping with consistency, is that, through my Sette 270Wi grinder the grind is fluffier than some other blends I have had and so has less clearance to the shower screen, so I've reduced from 18gm to 17.5gm to get a more consistent clearance. So ?17gm, 28sec, 45 - 50gm target. (VST 18gm basket)

I've also found that it's better to be less greedy and aim for a finished bean weight of 90gm rather than 108. The latter needing around 129gm bean and ends up tossing the baby out of the cot, so to speak!!

I think it would be useful to have a range of beans, and their recommended Profiles listed here, where folks have found them basically consistently enjoyable, for their taste, before moving on to more nuanced flavours. Looking forward to some feedback.

[Steve]

Hey Beanz,

Nothing specific to that coffee but I have been working exclusively with a Colombian last month and the following may be of help.

So the Classic at those power levels coupled with VST basket and 1:2.5 - 1:3 shot ratio will be quite bitter and roasty. To pull longer shots like that you really need a well developed lighter to med roast at most which taste good at higher extractions. Classic at 3.5 I would be looking at ristretto range 1:1 - 1:1.25 with a filter basket that is not VST, something with less holes / less flow.

I agree Firestarter at 3.3 is a mix of ashy and underdeveloped flavours, I added that to a blind cupping the other day just to refresh my memory on it. I think that style of profile has potential on this machine just that the Fan Profile needs to be much higher closer to what Damian did in the Chasing ROR thread.

I also use VST 18g basket and prefer higher extractions of well developed light to med roasted with 1:2 the minium starting point.

This is my latest profile (100g green) I have been working on if you want to give it a go. It uses a Fan Profile similar to Damians but lower RPMs and its giving me a pretty smooth Power profile.
Note the First Crack temperatures are much higher due to the static Fan Profile from 5:30 onwards.
I have saved the Profile file at Level 3.0 which sounds like it might be around your level, around 14.5 to 15% weight loss.

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[Beanz]

Steve, your post was so helpful. Wish there was a big LIKE and Thankyou option here!! [Looking at you, Chris ].

What great advice. I will look to using your profile tomorrow, sticking with this bean initially, for comparison

When saving the profile there are two warning messages, advising to tweak the power settings. As I understand it, we ignore these and drive on .

I started out, a few months ago, with reputable commercial blends and sticking rigidly to 18gm, 26s and 36gm. But a couple of oopsies saw me hitting 28s and 60gm and being surprised at the smoothness and richness. Trying to reduce channelling has been my real nemesis....but we're getting there!!

I am tending to do two batches at a time to get me circa 200gm to allow for dialling in the grind and getting 3 days or so use. Do you tend to 'rest' these a couple of days or rip straight into them? I'm putting them straight into a vacuum container and waiting for removable labels to arrive (thanks to tips from Sam and BenR)

Thanks again for your contributions here Steve.

[Steve]

No worries Beanz just sharing my findings as I go.

Yes you can ignore warnings, generally ive found the default pre heat power setting can be reduced by 100 - 200W depending on profile design. 120g the default would likely be neccessary.

I like to wait at least 3 days before cupping and 5 to 7 days for espresso. Some roasts benefit from extended resting times particularly if espresso is its intended use.

A neat cheat ive found works well for testing.
Using a medium fine cupping grind or filter grind, grind a roast thats only a couple hours old or straight off roast, seal in ziplock bag with air removed and leave it overnight to be used next morning. Can lose some high notes but otherwise gives a clear representation of how it will taste after 5 to 7 days rest.

[Beanz]

Just while I'm waiting for Steve's 8Min to rest I'm finishing up the Firestarter 3.1 roast. I'll be glad to see the back of them: After day 6, you will see my notes under 'About this file'. Yuck, underweight, not a great mouth feel, at first, fruity and slightly bitter, afterwards, a lingering ashy aftertaste. Unpleasant.
I exclusively aim for double espresso. ie 18gm, circa 26 - 29s and, preferrably, around 55g out but whatever works for a sweet and enjoyable full bodied experience with smooth mouth feel.

[Steve]

Whats your Voltage like?

Im usually at 240V, can go up to 242 and down to 237.

The only problem with these higher/static fan rpm roasts is people might run into trouble on darker roasts / higher Levels. Ive pushed the above profile to 3.3 with 240V / 100g batch size and it went a bit over 1400W towards end so needed Max roast power set at 1450W. After this and if you have lower mains Voltage the power will flat line / tap out which is not good. If it happens in the last say 30sec before cool maybe not an issue??

Blind cupping continues to suggest that if the power profile goes flat for any great length of time, particularly at the end of the roast the coffee will have variable levels of roast defects and baking.

Im really starting to think extended periods at / after first crack are not at all neccessary with this roaster. 100g is such a tiny amount and development is happening very quickly especially with such high convection.

So im thinking for a darker roast if you hit a higher temp quicker after first crack with a slightly shallower ramp to first crack, say 8:30 to 9:00 FCS, which will require less power to get there but hopefully keep the power profile steadily increasing with a declining ROR should give a sweet roast but with the deeper slightly darker caramels.

Anyway ive pulled some shots at Level 3.0 around 1:3 and im not getting any significant over roasted or defects flavours which is a good sign.

Im going to do some simple Brazil, low acid, sweet caramel / choc at 3.3 for 1:2 espresso and see how it goes. Otherwise next project might be to try and make the darker roast as suggested above.

[kaffelogic]

Just while I'm waiting for Steve's 8Min to rest I'm finishing up the Firestarter 3.1 roast. I'll be glad to see the back of them: After day 6, you will see my notes under 'About this file'. Yuck, underweight, not a great mouth feel, at first, fruity and slightly bitter, afterwards, a lingering ashy aftertaste. Unpleasant.
I exclusively aim for double espresso. ie 18gm, circa 26 - 29s and, preferrably, around 55g out but whatever works for a sweet and enjoyable full bodied experience with smooth mouth feel.

Your log 0011 has 28-29.5% DTR (depending on when you take first crack as recorded in the log or as in the comment). Slightly bitter and ashy notes are usually present as you approach and pass 30%. Perhaps you should stop the roast at 22-23% on this profile (level 2.4) to get more sweetness and less ashiness?

[Steve]

My cupping notes suggest that Firestarter is underdeveloped and it relies on the darker / tending to ashy notes at higher Levels to cover up the slight green astringency. At lower Levels 2.2 - 2.5 this green astringent note is worse like sucking on a tea bag. Along with the very steep decline in ROR and power profile just before and during first crack its likely baked as well.

All my latest cuppings have been with the Rao / Regalia Roast Defect Kit, underdeveloped, baked and good samples of the same excellent quality Colombian. It is a worthwhile investment if one wants to expand their ability to taste. I claim no level of superiority just working towards to best roast possible.

[kaffelogic]

My cupping notes suggest that Firestarter is underdeveloped and it relies on the darker / tending to ashy notes at higher Levels to cover up the slight green astringency. At lower Levels 2.2 - 2.5 this green astringent note is worse like sucking on a tea bag. Along with the very steep decline in ROR and power profile just before and during first crack its likely baked as well.

All my latest cuppings have been with the Rao / Regalia Roast Defect Kit, underdeveloped, baked and good samples of the same excellent quality Colombian. It is a worthwhile investment if one wants to expand their ability to taste. I claim no level of superiority just working towards to best roast possible.

It's great to have this feedback Steve. We are aware of the need for an improved set of base profiles for the Kaffelogic and are currently actively working to curate a serviceable set. This will allow us to replace profiles like Firestarter with profiles that are closer to the optimal that you are also working towards. Over the next few weeks we should have some interesting developments which we will post to the forum, and will look forward to your comments.

[Steve]

Sounds good Chris, I look forward to trying them.

The 8min profile above is coming along nicely for a lighter roast, stopped a natural for filter mid first crack after about 40 sec and it is fully developed. For Max Level dont go over 3.2 as the profile is too steep and runs out of power / starts baking and getting bitter.

Here is a slightly longer 9min Darker version which I've pushed to Level 4.4 with a tweaked Fan Profile and could likely go a touch higher depending on power availability. Have only done an impatient cupping of this as its work in progress but the power profile on roast log looks very promising and will be interesting to try as espresso / in milk in the next week it seems Choc caramel heavy which was the intention.

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