Long roast

[rresidorinucd]

Hi all - did a larger charge today and it seemed to draw on a bit. I’m wondering how much the larger charge (~1.5 lbs) contributes to this length. It was an Ethiopian (Natural) and it just seemed to keep going. I’m not sure if I just coudn’t hear the cracks or what but does a specific temp on the IBTS always mean it’s cracking. I.e. if I just went by temp alone, can I count on it hitting FC and such based on temp alone?

I’d love any feedback you can provide. It seemed to stall out a bit so I fudged the power slightly from the playback I was using (it called for a P3 but I stepped it back up to a 6). Is this generally too long of a roast for this size?

[blacklabs]

I don’t think 13 mins for 755g is that long. My 1kg roasts ranges from 14+ to <17 mins while my 500g roasts ranges from 10+ to <12 mins. The one time I did the odd 630g it was around 13 mins.

You might want to start with an F2 or F3 at charge. The P6 and F6/F5 I see there before FC you’re probably losing heat there thus losing your momentum for the roast.

With my roasts regardless of batch size most of the time I would get FC around 395-410F. I call my YP (yellow point) somewhere in the 330-340F depending on the moisture in the bean - basically when most of the green color is gone, average is around 333-335F

There is a link to a temp table with degree of roast milestones somewhere in these threads that you search for that you might find useful as a reference.

[kkrawford]

You didn’t say what the ambient temperature was but in my part of the world it’s winter now and I find that I have to keep fan speed down in order to keep the momentum up during the roast. Your roast appears to stall around 7 minutes . As always, the only thing that matters is how it cups. Let us know.

[jimmybulletroaster]

How low is your fan speed?

I find F1 imparts a bit of the drum flavor.

F2 is fine, but chaff builds up. F2 still has a slightly more smokey aroma.

F3 the aromas clean up, and the chaff is less prominent as much of it gets lifted away.

F4 heat retention begins to become and issue in the winter. Requires higher Power settings on heat to get similar time/temp landmarks.

F5, i’ve not really used.

I find myself often wishing i had an F2.5 and F3.5, as i’d likely use those in addition to F2 and F3 the most often. Anything outside of those settings feels a bit imbalanced. I’m going to experiment more with F4 and higher P settings, but with a 120v board, i tend to prefer to have the headroom. Especially in the hotter months.

[billc]

A work in progress.

This was for an Ethiopian.

The second crack numbers are unverified as I seldom went into second crack when I built this.

The original data was from Thompson Owens of Sweet Marias

[alghamdi.majid1b1s]

Hello,

There are many things to say, but as per your chart, your roast mostly will be flat, you lost the momentum during the roast phases. The reason is your charging temperature.

Now, put aside roast phases, did you like the outcome of this profile!? If you did, then no need to change it. If not, then what I will write next may help you:

1- High Altitude Beans : like ethiopian, mostly with high density, thats allow them to observe more energy than lower altitude, and faster. You are roasting 755g almost not far from the recommendation (80%) of the drum’s capacity (1 kg). I would recommend you charge 200+ C degrees. That would shorten all the roast phases, the result will be higher acidity, less bitterness and more clear fragrance and noticeable fruity notes

2-Variable Fan speed, in the early stage of the roast, during the yellowing phase, you need to maintain the momentum, low fan speed (f2-f3) for example, then (f4-f5) after the yellow point, you risk losing some of the built energy inside roasting chamber, but increasing conventional heat transfer helps to achieve more clarity and more fruity notes, ahead of the first crack (around 180 degrees), fan speed (f6-f7) to kick the smoke out of the chamber and get a cleaner cup as a result.

Finally, understanding what you really desire to get will help you either follow the whole instructions i mentioned, or follow what ever suites to achieve your goal.

In my opinion, there no single right way to do things, but there are many suitable ways.

Hopefully it would help you.

Have a nice roast.