Maybe I mentioned this or not, I am using an external fan under the roast’s board. It may malfunctioned due to the board’s overheat.
I will try to add a cooling fan. I think that 120v would overheat sooner than a 240v
You might want to try cleaning the glass on your IBTS. I suspect that will fix your readings. Typically when you see crossover in the graph, IBTS is dirty. I clean it pretty much every other session to make sure it stays clean and accurate. Since the machine relies on IBTS for preheat temps, it’s important it stays clean for repeatability and consistency. I suspect you will also find it more accurate/reliable at measuring color later in the roast as well…
Hello,
I have a weekly cleaning routine, I do it to keep my roasts consistent. I do not have any color issue eith my roasts, I can roast 3 different profiles and end up with the same color of the roasted beans (thats what you practice in SCA basic roast). IBTS suitable for small batches, mostly because they are rotating below the thermal coupler probe. But for larger batches, definitely I will prefer the BEAN Temp. I explained previously, but I will put more details to make it clear scientifically.
There are two major transmissions in roasting, Endothermic and Exothermic, when exothermic occurred, the beans release energy, that will increase the overall energy in the roasting chamber. This extra amount of energy, IBTS sensor doesn’t read it, though it will impact the roast process.
If your IBTS stayed above the Bean Temp, thats happened either you are roasting small batch or you didn’t preheat your machine enough.
Did a quick tasting this morning with a couple recipes.
Keep in mind, that even though i am taking directions from others, that my experience in no way reflects the same flavors and end result that they get, this is simply to see how well recipe’s translate.
Coffee used was a mid grade Costa Rican coffee that has a mellow apple acidity and a slight baked spice and subtle chocolate finish typically. But it has aged out a bit, and lost some of that sparkle.
3 recipes:
350g by @jondemir
“Hoosian” i tried something loosely based on some things i had seen on Rob Hoos’ profile. I dare call it ‘Hoosian’, but for lack of a better descriptor at this time.
The third roast was something somewhat more generic in terms of what i’ve seen being common approaches lately. moderate charge around 205C, moderate fans to start, and stepping up in fan and down in power as the roast goes. 1.5min dev.
BREWING:
Brewed a smaller 30g in Chemex, 1:15 ratio with a 3.5minute target.
The cup impressions:
-
Jp’s was fairly solid. This roast had a more muted flavors, which considering how the roast began to fade in energy towards the end, as i let it ride out, that makes sense. I assume my fan setting or power settings are effecting the overall energy of the roast, and i might push it a little more. That said, it was pretty great how well his recipe translated to my roaster, and how well it brewed.
-
hoosian brewed about 15seconds faster than the other two roasts, i brewed it twice, and both times it was pretty much exactly 3min15seconds. At this point my palette is over worked, so i’m not going to redo it. Something to note anyway. I felt like this one was the cleanest overall flavor, and brightest acidity (without being harsh). I am assuming the high fans were the reason for this. EDIT: as it cooled to roomtemp, i felt it was a little unbalanced, perhaps a combination of too high of fan and a short dev. It had some unevenness looking in the bean, however on the exterior it seemed more even than the others. That said, was clean and bright, and shows potential.
-
Generic approach, while i don’t think this was the best version of the Costa Rican coffee, i sort of felt it was the best of the three. a bit more depth and rounded acidity than the hoosian hi-fan test of 2. This one may have also had the most even look, cracking open a few beans from each roast. i kept the fans high enough to promote even roasting, and went a but higher in temp then the other two. so, not like all things were equal. But certainly was not as clean tasting as the ultra hi fan hoosian concept. just goes to show that the conventional wisdom on this forum is on the right track, perhaps.
Depending on the coffee or mood, anyone of these could be preferable to the other. I find the hoosian approach very interesting and may try it on something more fresh and bright.
i feel that Jp’s 350g recipe could be a great starter toast because of how well it translated. With a few small tweaks, it could work perfectly on my bullet. that’s pretty amazing. i’ll add his to the list of small batch recipe up top of this thread. Thanks @jpndemir !
Thanks for trying it out!
Let me clarify that the recipe I suggested Is just a variation of Morten Munchows “get to know your roaster”-thingy
I found that I could roast pretty much hands off(when I had a computer) and get results I wanted by just tweaking the recipe here and there after cupping. I use the same strategy for all batch sizes and usually fiddle with fan settings if roasts get too “cloudy” or “smoky”.
I let the beans ride, tweak for next roast and let the beans ride again.
Currently everything is happening manually but here are 3 roasts where I tried a new bean for the first time and had access to a computer:
Hope it helps, cheers!
Hoosian…I like it
could also have Raoesque and Munchowish profiles as well
I think if you follow the usual pattern that English uses in forming these sorts of words, coffee roasted ala Morten Munchow would be described as Munchovian.
-Gray
that is a definite improvement!
Was this a 120v and 1Kg (2lbs) of bean?
That curve looks good. Nice energy up front. Very short development, what kind of coffee is this? Natural Ethiopian?
120V, Ethiopia Guji G1 Organic Mormora Natural 2022, 800 green /w, 700 dry/w
Interesting. Makes sense. Thanks.
Does that mean that a bean you’re thinking about roasting using that method makes that bean the Munchovian Candidate? (ok, ok, I know. A bit obtuse).
Time to revive this thread. Another season, and other roast!
How has your approached evolved or changed? Doing anything radically different? Or finding a nuance in something you already love?
I think the most dramatic shift in how I viewed the bullet, was seeing the Sweet Maria’s roasts. Made me rethink what is going on, and what is possible.
But the main impetus for reviving this thread is the Andrew Coe curve. He seems to have embraced the more conventional approach, which is nice to see. After so many weird curves and experiments, it is nice to see a grounded approach that looks logical.
Anything about his approach stand out to you?
I’ll add personal roasting sidenote. Yes, I like the more conventional approach and thinking, but two days ago, I attempted a 2lbs (900g) batch, and as maybe a couple of you know, the 120v machines don’t like P9, except in very moderate or cool environments. So, I think this batch failed maybe 3 times throughout the roast, making for a weird trajectory…. And yet, brewed it up this morning, and it is really really nice. Not my best, and not something I’ll recommend, but I enjoy it. Sort of a silky molasses, and very laid back neutral almost non existent chocolate power accent. Flavor got reduced, but the texture is really viscous. And just zero acidity or bitterness, despite having low flavor overall. Now I can taste where I needed more of this or that, but I guess to reiterate, that a good cup is a pretty wide spectrum, and I really am enjoying sipping on this specific roast of coffee, because it is a rainy day, and it just fits the day so well! I’ll try to reverse engineer what went on and share later, but at the same time, it wasn’t anything to copy, as it was kind if extremely specific to my setup and these beans, which these beans seem to be able to handle low fan and underpowered roasts really well.
I like the Andrew Coe curve and recipe too. Was most surprised by him using F5 for the duration of the roast. I am trying this next.
The roast on Münchow’s Coffee Mind course, which is free for bullet users, uses F5 throughout the roast. Just don’t forget to adjust your PH and power settings to compensate for the change.
Hmmm. I never noticed that before. Thanks for pointing it out. Will certainly try that sometime.