I wouldn’t know exactly and, as you’ve said, I don’t think that there are that many defects in specialty coffee or that I’m some kind of wizard in buying them, because none of it is true. I’ve had different size beans, from smaller to larger ones, all come out uniform with high fan, but also with low fan. It probably depends on the whole roast and how and how much heat it’s getting. Just wanted to add that I empty my cooling box before dumping the coffee because a lot of chaff falls out during the roast. After cooling, there’s still a lot of it, or a ton I should say, on the filter.
What is high fan to you? For a while high fan was F3 or F4, but lately trends have seen fans at F5 fairly normally, so high for some might be F7 and up
It depends on batch size. I’d say F5-F6 is high for batches from 500 to 700g. 800g and up to 1KG, I’d say F4 is high, F3 OK. Lower batch sizes, which I rarely, if ever do, have more wiggle room so there an F7-F8 might be considered high. You want to have room to take away the heat and up the fan approaching the end of your roast, so if you were to start with F7 on a 600g batch, you’d probably have to keep P9 for a long time, maybe even throughout, and you wouldn’t want that. But you must always adjust your PH and power settings accordingly when you change your fan speed. I think I’ve heard Rob Hoos, maybe even in his Vimeo course on the Bullet, I’m not sure, trying to do the whole roast with just fan adjustments, but he wasn’t very satisfied. That’s about as much as I can give you. Hope it helps.
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Where did you buy this coffee? Many Ethiopian coffees are aggregated lots from washing stations. So you’ll have a variety of farms, regional landraces, elevations, etc. all combined. That can contribute to the unevenness you are seeing. If the coffee tastes good, I wouldn’t worry about the visuals.
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I purchased the Ethiopian Yirgacheffe coffee from Sweet Marias. It’s a washed coffee where the station gets coffee from 500 small farm farmers. So yes there’s high chance of variability there.
The roast in its entirety is rather consistent.Here:
I’ve circled what I think are semi quakers. Minus that, roast color is consistent throughout. Lighter colored chaff in the bean crack is consistent behavior for washed coffee.
Zooming into one bean, here’s what I call freckling. Hoping it’s visible here:
If you look at @braca19452f9m image at top of this chain, I don’t think it exhibits this, at least not to this degree. I’m guessing this is characteristics of the bean and nothing I could have done differently while roasting?
Well, the freckling is pretty normal, and your picture looks nothing like those above. The couple of lighter ones are also normal. I get that with some beans. To me, it looks pretty uniform. Maybe Andy has something, but to me everything looks good, including the profile.
Sorry I hijacked the thread.
I think @davidstultz7.n8Fr could benefit from trying a different bean and seeing if unevenness reoccurs.
This video explaining color unevenness comes to mind regarding the bean he’s using.. While inconsistency more common in naturals, I don’t think all wash stations are alike. It could be possible that the less ripe beans aren’t being surfaced properly and removed. That could result in more quakers/semi quakers and unevenness.
Hey guys,
I actually had similar question recently. So let me also drop my observations here. I’m sure Professional roasters have figured this out long time ago, but I also want to know what am I doing wrong as I am still learning. Only way I could improve on much more even roast, is when I lowered down Power setting and roasted for longer.
I did however try few approaches, which led me to even more questions…
First approach I’ve used was Andrew Coe’s recipe where I have steady Fan setting and Drum speed is set to 9. Roast curve and time can be seen here:
Result can be seen below:
I do however have one issue with above roast, and its short kind of roast time… You get freckling, you get chaff still on the beans, and what I get with 8min roast is absence of smell and taste… So I decided to have slightly different approach, and increase toast time. And went around with following curve.
My result was as follows:
Texture wise kinda same, freckly, less chaff on the beans themselves, and muuuuch much more smell and taste after taking that roast to 13min…
My observations were following: lower the power settings and longer roast duration gives me much more aromas in my product, however I still cant figure out what will give me much more even bean texture like @braca19452f9m has shown above…
So I went and bought Ethiopian, washed Yirgacheffe from big production roaster and can clearly see where I am just not there at all. See their beans below:
Big production roasters, have all three factors aligned…
- Roast is very even, all beans are very evenly roasted without “freckling” they have that light chocolate texture, very even and nice colour
- No chaff stuck to the bean itself… Whereas I am getting that chaff on some beans and its even hard to peel it off.
- Middle bit of the bean itself where you can see chaff in center if roasted out and is not white, whereas mine has this distinct white line in the middle… Theirs seems evenly roasted out…
So here I can say, I’ve tried both, rising preheat temperature vs lower preheat temperature with higher power setting down the line and making roast time longer vs shorter, but I am still kinda getting same result… Only difference I get, is sensory, where smell is very nice at longer roasting duration…
Where can I improve to get that nice even brownie kinda looking beans and retain all of the smell and taste.
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Those are good. I often find similar observations, though it is not always apples to apples. naturals with excellent inherent flavor can and do taste good at different roast levels. It just depends on the goals of the person roasting and the bean, as well as other factors.
Aillio engineers decided that the Bullet is primarily conductive heat transfer, but most professional drum roasters are primarily convective heat transfer. So the Bullet is going to be less even and less thorough.
Are you judging smell and taste immediately after roasting? I notice that many of my roasts smell like nothing special straight out of the roaster, and for a few days thereafter, but Ethiopian and Yemeni varieties really only come into their own 5-7 days after.
It might be interesting to try roasting your short profile and your long profile in a single session, wait a week, and then blind cup both.
Disclaimer: My nose and palate aren’t all that discriminating.
Also, you mentioned that the roasted coffee you bought was from a washed lot. Is the photo of your Bullet roast a washed process coffee, or natural?
Hey Jimmy, thanks for reply. Thats unfortunately something I wont be able to compare as I simply dont have access to professional drum roaster. But something I’d keep in mind comparing my roasts to theirs.
I’m telling you, that is how drum roasters typically work. aillio does convection as well, but it is not designed to do as much as a normal drum roaster.
Hey John,
I can see you hitting few points that I will actually need to investigate. I will definitely do a blind tasting comparison of both roasts back to back. And yes I do compare straight out of roaster(smell wise), cup after 8hr. But havent actually thought of doing side by side comparison of different length roasts. And also now I’m curious seeing them compared to each other lets say 2-3 weeks later as well and see which one actually tastes better after resting.
You also hit a nail straight away, by mentioning process. I can see that big production roaster beans that I had, were “natural” process and the one I’ve roasted in images above was washed process. For that reason I checked my Brazilian roast that I had done earlier, which was also natural process and I was surprised to see that it was much much more even in colour and also way less chaff on the beans themselves and no “freckling”. So it really appears to me that naturally processed beans not only roast more even, but also have less chaff after roast which is a surprising discovery and I havent read that info anywhere before…
You can see how chaff is less defined is middle part of the bean on Brazilian natural process in my example below… Sorry light is different but you got it right with mentioning process.
Hi @lagodecafe , I really doubt that the professionally roared Ethiopian beans you bought are washed beans. They look like natural beans which explains the absence of the white strip in the middle of the bean. I used to buy professionally roasted Yirgacheffe coffee beans for MANY years before I started home roasting my own and they always had the white strip in the middle of the bean.
The only ones that didn’t were natural beans.
Don’t stress about how your beans look, judge the taste only. 
Thanks @gabyritaseek.qiAO! Yes you are correct and I’ve mentioned it above, production roasted beans I had were natural process. Before today I somehow didn’t link process to bean appearance.
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Well, I think we might have finally gotten to the bottom of this one. I sourced some very fresh Ethiopian from a friend of mine. Right when I got the coffee, I was shocked at the difference between his coffee and the Yirgacheffe I had been roasting. After reviewing with him, he asked the age of my coffee. I wasn’t completely sure so I had to go back and look - end of 2022!
Now, I know there could be some other factors but it seems like the age of my green coffee could have been the issue here. In the photo attached, my initial Yirgacheffe is on the right and my new green coffee on the left.
Sure enough, roasted a batch last night and saw much more consistency across the board.
Oof! Yeah, anything past 6months starts to really show. Particularly after 12months.
Assuming that these coffees are from the same mill, same farm(s), same process and everything else, just different crop, I see it more as improper storage than a bean deteriorating that much over such a short period of time. Also, the inconsistency thing would be in the selection of beans, not that those beans age inconsistently. Nothing to do with photos as they don’t really say much. But anyway, whatever makes you happy is the best thing. If you think the only way for you to get a decent cup is a fresh crop, don’t buy too much of it, or don’t buy who you bought from the last time, because improper storage will ruin them much sooner than a year, while proper storage will make them taste the same as the first day for a long time. Coffee can be ruined in a couple of months. And before someone asks what’s proper storage, there’s lots of info online about it.