First Roast

Super excited to have done my first roast today - actually, 3x400g Monsoon Malabar roasts back-to-back. Letting them rest and will taste them all tomorrow. The roast profiles are in betaroastworld if you’d like to comment on them, the analysis is very much appreciated. Roast World - Cup, grade, and analyze your coffee roasts in depth


Very exciting! Those look like nice roasts, probably just into second crack? Reading the description of monsoon processing, that sounds like a good roast level choice :slight_smile:

The 3 curves show the cooling effect of the fan, causing the red RoR curve to drop after FC. You can also achieve this with a constant fan speed by decreasing power, but with more time lag before the curve responds. Some argue that manipulating power instead of fan results in a better cup. It’s something to play with anyway.

The IBTS temperature at FC is usually very reproducible for a given bean, but yours had a little variation (210C, 212C, 207C) so maybe you didn’t use exactly the same criteria for deciding when to mark? Knowing that temperature is be useful if you want to make changes in anticipation of FC, say reducing power 45 seconds early.

One of your roasts showed more weight loss, but otherwise they’re pretty similar roast levels. Curious to hear how they compare in the cup…

Hope all this blather is what you were looking for!


Thanks a lot @bradm appreciate you taking the time to comment. I’ll investigate all these points and let you know how they taste. Just got the kettle on now!
btw - does anyone know what the amps per power level are on the R1?

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The power levels are:
0 350 500 650 800 950 1100 1250 1400 1550W
You can divide this with your voltage to get the Current (Amps)


Thanks Jacob, that’s brilliant. Appreciate your fast reply

So, what did you think? Did like one’s taste the best? I haven’t roasted Monsooned Malabar in a few years and never on the Bullet.

@wngsprd thanks for your reply. Now then: I cupped them all about 24hrs after roasting.
Roast 1 is disgusting! Totally astringent, sour, nasty taste! Tried it with milk and as espresso - yuck!
Roast 2 is developing into a pleasant cup. It was quite bright, good caffeine hit. A bit light on flavour, though smooth mouth-feel. Could have been developed a bit more towards medium-dark, maybe even 2C would have fit this roast well. I think the roast time was about right but a higher drum PH temperature could have helped to drive the roast.
Then Roast 3 smells musty, and has a damp cardboard taste. Maybe there are quakers and defective beans to be sorted out. These weren’t good quality beans tbh.
So, for me Roast 2 seems to bet the better of the three, though it also could be improved further.

Glad you mentioned quakers…

On a few occasions I’ve found what I thought were quakers but later decided they may have fallen from the bean chute late in the roast since they seemed to be responding to the roast heat.

That’s when I noticed that green beans can get left behind in the bean chute when I charged the roaster. It’s just 1-3 beans that might linger at the bottom of the chute or on top of the indexing bar that the funnel rests on. So I developed the habit of checking the chute after charging to confirm everything has dropped into the drum.


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Using the link above the pictures, the title “Scott Roast 1” corresponds to the bottom picture which had 16% weight loss. Was that the disgusting one? The others were only 14% weight loss…

@bradm yes indeed, Scott Roast 1 is the undrinkable one :face_vomiting:

Scott, Glad you got a drinkable roast. I think monsooned coffee is a challenging one to start with.


@wngsprd thanks for your thumbs-up. I’d heard MM was a bit tricky to roast and i like a challenge. Now, it’s drinkable though not in any way amazing. I have got some Kenyan and Panama beans to roast next. Any experience with those?

@wngsprd @bradm STOP PRESS! Guys, you’re not going to believe this! So, I kept all three roasts in an airtight container, opening the lid every day to allow to degas. And this morning I was going to throw out the “Scott Roast 1” - this is the one that tasted horrible at cupping +24hrs after roasting. so I ground 18g for an Aeropress and … blimey! that’s a pleasant cup of coffee! What’s going on? It seems to have developed itself over the past week into a bright, mellow coffee. I’m looking at the curve again Any comments?

Seems like “Never give up!” is correct. I notice a big improvement with some coffees as a day or even a week goes by. If I’m going to drink a roast within the first 24 hours, I grind the beans and let them sit out for a couple of hours before the pour over.

Glad to hear your roast isn’t a throw-away. Some of mine are good immediately, but lately I’ve been trying to let 'em rest for a week. Makes you wonder how good one of the ones that you drank up right away could have become.

Hi, I am also a new owner of the Bullet R1 V2. As every new owner very excited, even can barely sleep at night (or is it too much coffee!?). For my first roast I picked a Colombian Supremo (size 18) and followed to the letter the recipe “A Beginner’s Roast Recipe” in the article “How to Begin Roasting Great Coffee on the Bullet R1 V2” (light roast) on the aillio website or owner manual (I think it’s there too). I got great success, clean cup, well balanced (fruit-acidity), good coffee taste, amazing smell. That was 2 days ago and I cannot post the graph as I couldn’t connect to roastime at that time (driver problem!). I reapeted the recipe with a Brazilian with the same success (slightly less developed). Now the problem is fixed and I will experiment using the roastime software. I agree with wngsprd that a Moonsoon Malabar is not an easy roast (whatever the roaster you have). I say that based on my 4 years experience roasting with a Gene cafe.

Anyway, take what I am going to write lightly as I have virtually no experience yet with the Bullet. Looking at your graph though and based on my experience with the Gene, your RoR is too high at first crack and more importantly does not decline constantly enough during the yellow stage. You say the first roast is not good and I am not that surprised given your RoR rise just before the first crack (ie right after 8:30). With the Gene cafe, I got excellent roast with RoR between 6 and 9 at first crack. My readings on success roasts with the bullet showed RoR at first crack around that also. To be explored I guess.

My guess is that you put the fan to F3 too late in the early stage. My understanding (and I might be wrong) is that we should not increase the fan after 120c and before the first crack. After 120c (near 3 min in your curve), increasing the fan will have a convection effect, potentially increasing the RoR or minimally preventing it to decrease. when I look to your first graph, that is what happen when your turn the fan to F3 near the minute 6. I have read in the manual that above f4 it has a cooling effect instead of convection effect. That probably explain the too fast RoR decline when you hit f4 around 8 min. I have read that a good time to increase fan speed (from f3 to f4 for example) would be 20 to 30 seconds before first crack. that would have been right after minute 9 in your first graph. However, if you modify the parameters at the early stage it will certainly affect the time of the FC. So I guess that is what we have to experiment (ie the right recipe for a specific bean and environment). I also read that it is preferable and easier to control the RoR with decreasing the power heat than the fan. I will try to put F2 to F3 at 120c and not touch it just before the first crack, so I guess I will have to experiment before being able to do that.

So all that is theoretical right now (from my readings) so take that for what it worth. However, I am pretty sure that the problem with your curves here are within the maillard stage (ie from yellow to FC). Today I will try the recommended recipe but this time with the roastime software 9to see if the curves correspond to what I taste). Sorry if my english is not top notch as this is my second language.

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My 4 years experience with the Gene cafe roaster told me that a success roast taste always good right after the roast and improve with time. and a great roast taste amazing right away. I found that some beans are even better after 4-5 days, most after 7 days and some reach their peak at 14+ days. When I visited the Starbuck R&D facility in Seatle in 2016 the master roaster said they let the bean degas for 7 days before distributing. Not that I am a fan myself of starbuck coffee (otherwise I would not roast myself!) but they are still professionals with many years of experience. I have had mediocre roasts over the years turning into acceptable roast after few days.

Hi Again,

From theory to practice. I roasted a Colombian following the suggested recipe in the owner manual without trying to adjust anything (ie not looking at the curve to make adjustments). You can see the curve here.

It gave a decent cup but to me it is clearly underdeveloped. I roasted the same kind of beans in my Gene Cafe and it is soooo good compared to what I got with the Bullet. I noticed that the development time is quite high relative to the 20-25% everyone is talking about. (with the gene I always got within this range without even trying to). To me this batch tastes coffee with underdeveloped notes. So not totally to throw away but I cannot say it gives me much pleasure. When I crush a bean it smells good (but not close to what the bean smells with the Gene). So I guess if I would have stopped to get 25% development (instead of 37%) the coffee would have been undrinkable. I do not know what I have done wrong as the RoR does not look so bad. what do you think? If I raise the charge temp, the first crack comes much too early but the bean is a bit more developed (but too dark for my taste).

I also tried with many 200g charges (at different charge temperature) and it is impossible to get a good reading out of it. (and I throw away all batches because they were too green for me; I do not mind fruit and acidity but it has to taste coffee to not just fruit and acidity like many people like). So I guess 350g is really the minimum. I ordered cheap (6$/pound) but good beans from Brazil to experiment further.

@kafcafe Hi, Hello and wow! Thanks v much for taking the time to give me such a thorough reply. Appreciate it. So. Here is my annotated roast curve with your notes added.
If i roast a la Aillio manual, we can see where the curve adjustments would be.
You explain the effect of F3 and F4 in the curve - cool.
And you describe well the ROR at First Crack - hadn’t known that before.
I’ll also make a roast following the Aillio manual as you did.
Which brings me on to my next questions for us: How do we plan a roast recipe with this knowledge?

  1. What decides the Charge Temp?
  2. What decides the End Temp (Bean Probe or IBTS)?
  3. How steep is the declining ROR curve (as an angle)?
  4. Should the curve ever be horizontal at any time, or is that an indication of baking?

@kafcafe btw, your english is top notch. Better than mine and it’s my first language!! :slight_smile: