Case17 wrote:On my bullet, I would say I pretty consistently see 195C - 198C for 1st crack, with maybe 200C on uncommon occasion.

Thanks for the tipping on shortening tthe drying phase & extending the maillard! To make sure I'm understanding correctly, this is a profile in which the slope of the ROR is more negative? In other words, it is very high in the beginning (to speed through drying) and then lowered as you approach maillard? Alternatively, I might go for an exponential decay line shape, where the ROR is very high and then rapidly drops when I get into maillard. Do you have any example profiles to illustrate?

Here are two:
- Tips for roasting an Ethiopian natural
- Tips for roasting an Ethiopian natural

Thanks, i had seen this thread but not realized you had posted there.

Case17 wrote:image

I have tried out both the keramo and the bombe. Both were alright, but not great. I assume my roast profile needs optimizing.

Hi Case, interested to hear if you have any updates. I pointed out that I'm charging at 275 C vs. your 300 C for the same 750 g load, but if you're not seeing any tipping, scorching, or divots in your roasts without a soak or lower charge temperature that's not necessarily an issue. I'm interested to hear what recommendations you've tried and what the effects have been.

Regarding my first crack temps, sometimes it's hard to hear first crack so I could be off, but I did load up several roasts on the roast analyzer a while ago to see where I was marking C1 and it did appear to be around 211 C. I did recently clean the IBTS sensor, though so I may take another look.

Hi there!
Currently roasting and will post back after complete with tasting feedback. I am switching down to 350g batch size, so there will be differences in the Power and charge temperatures.

yakster wrote:Hi Case, interested to hear if you have any updates. I pointed out that I'm charging at 275 C vs. your 300 C for the same 750 g load, but if you're not seeing any tipping, scorching, or divots in your roasts without a soak or lower charge temperature that's not necessarily an issue. I'm interested to hear what recommendations you've tried and what the effects have been.

Regarding my first crack temps, sometimes it's hard to hear first crack so I could be off, but I did load up several roasts on the roast analyzer a while ago to see where I was marking C1 and it did appear to be around 211 C. I did recently clean the IBTS sensor, though so I may take another look.

I roasted several batches today, and will update them here as I taste them. I'll give them a few days rest. Most of them I practiced drawing out the maillard phase by starting the roast hot and them greatly reducing the heat and increasing fan speed after a few mintues. Then I trickled into 1st crack and gradually got up to temps around 202-205C (IBTS) where I dropped.

Something I'm thinking about as I company my roasts and yours are whether the temperatures are accurate/comparable. I guess they probably are... I assume Aillio has done a good job here. I'm just confused as to why your first crack is so high, and by extension, why your drop temps appear to be high. Typically, getting into 210-215C is gettign into city+ roasts, which is usually (but not always) beyond where the fruitiness of natural's shines. But, I am not an expert. Anyways, along these lines, I wonder if the issue could be defining what first crack is. Are you selecting first crack at the first few pop sounds, or when you here the 'rolling' chorus of first crack? In addition, I should mention that I have found it pretty difficult to hear first crack with both Keramo and Bombe on the bullet.

Anyways, the reason this is important, if you are getting really nice fruit flavors at 212C, then maybe that is literally accurate and I should be going longer in my roasts. I've done many batches of SM's Ethiopia Kayon Mtn Taroo DP,which I usually roasted to 206-210 C. Around these temps (usually with profiles with steadily decreasign RoR) I find the coffee very pleasant with a lot of body and some sort of fruitiness... I wouldn't call it berry, but a certain pleasant fermentation flavor that I typically taste with Ethiopian DPs. But it definitely wasn't in-your-face berry notes, which the coffee was supposed to have. So, I sometimes think that getting to 208C or so is getting too hot. Also, this may highlight some of the problems with taste analysis which is highly subjective and not quantitative.

I roasted a batch each of Keramo and Bombe to higher drop temps (208-210C) to test some of the above ideas out.

Oh, one more thing. To your point about defects related to overheating (tipping, etc...)... I am not an expert, but I did not see anything that was obvious, though perhaps a better trained pair of eyes would see more. When I get to posting more profiles as I taste these, I will see if I can get some pictures of the roasted beans. The one exception is my very first roast today, which was absolutely over heated (too high charge temperature). The roast level bean-to-bean was highly variable and a number were scorched while some were underroasted. After that, I raised my batch size but kept the charge temp the same. That said, I think your concern that I may be preheating too high is legitimate, and the next time I roast I may play around with this.

Case17 wrote:Any opinions on these?

Ethiopia Sidama Bombe (DP): Anyone tried this coffee out? Was thinking of buying some, curious if others found it as fruity as they say.

Currently drinking the Bombe roasted using Aillio Bullet. It was roasted to about City-City+. Rest it for 2 day and start drinking it on the 3rd day. it was so fruity the first 3 days and after that, the nuttiness show up which produce a much balance cup.

We mainly drink latte and the milk can't cover the fruitiness. I like this bean a lot.

NOTE: The size of the bean is very small and boy it was hard to listen for the first crack. I end up marking the for the first crack based on the IBTS reading on my aillio bullet. Will attempt another roast this coming weekend.

yakster wrote:I got a good amount of berry, my IBTS normally reads around 211 at first crack.

I'm also using the buttle v1.5 and my typical FC range is 198-203C. 211 seems a bit high.

here is my Bombe roast curve.

https://roast.world/r/Tvlgdzgvkg12gBISNj7v5

Interesting. What is your final temp on the IBTS? Looks like 210-215, which seems rather high?

The bombe bean was dropped at around 209C right before it hit 210C. I rarely roast anything over 212C.

My IBTS also reads between 195 and 205 at first crack consistently. Usually it is closer to 195-200