Does anyone can say about my graph is there any fail or mistake? Or any recommendation? Thanks.
Are you sure you got to FC at 186.9C? Generally you expect FC to happen between 196-205C. Your drop temp is below where I normally expect to hear FC start.
So your roast is just way underdeveloped. Sometimes it can be hard to hear FC. If that is the case, just pick a number (like 196) and use that as FC and then time your development phase from there.
Yes, I wasn’t sure about my FC. I will consider that, thank you so much.
To my eyes your graph looks quite decent and well controlled. The roast is in the light side as you said so make sure you give it plenty of rest time before judging how it tastes.
In my experience with Ethiopian beans, some of them can take as long as 6 to 8 weeks to show their true colours.
Also, for what it is worth, I have had a few beans where FC occurred around 186degC so that’s not totally unusual. 
Here’s my opinion, take it for what you will. Using the bean probe, it is quite OK to have FC at 186. I suggest using the IBTS for batches under 800g. I think the preheat is excessive for a 600g batch. Since it is a washed coffee, I’d suggest spending a bit more time in the Maillard, and a bit less in the drying phase, and I would allow for a 30-40 second soak before hitting it with full heat. And also what gabyritaseek.qiAO said about resting.
I noticed that cleaning the IBTS on my R1V2 made a big difference in 1C temp. Before cleaning it was consistently at 195C and after it jumped up to 205C.
Well, that’s more of a regular maintenance thing. I’ve never had that problem.
Thank you guys for your attention and contribution. Rearbarbers0h was right because i waited for until 195 to hear FC and i could clearly heared pops before 195c but waited for marking a little while for continues pops, then i marked.
For all of you, i share my latest roast graph may it help also someone, i did some mistakes end of the roast but i have hope. Tomorrow i will cup it and back here for the taste result.
Keep roasting guys.
Sincerely, Oğuz
Well, today I did a cupping, taste was better as before but not what i expected, much more flat and slightly bitter taste. I will look for improve.
Howdy:
I agree with @braca19452f9m about your preheat temp. For 600g batch, especially of Ethiopia (more dense), I would aim for about 270C preheat? I preheat to 300 for a 1kg batch of Ethiopia.
The reason for this has a lot of thermodynamics behind it. In this case, you probably need to give your coffee more time to “soak” up the heat from the drum. If you start too high, the temperatures reported by the bullet will be higher than what is actually true. This is especially true of more dense beans since it takes longer for the heat to penetrate. There is no instrument that can tell you the internal temp of the beans, but the aim is to have the internal and external temps be the same at the end of your roast.
I will say I am intrigued by having 13.6% loss and only roasting through 201C. I reckon that is because the moisture content is higher to begin with so you are losing more moisture. You might expect that % loss to be higher than other beans, if my theory is correct. On that note, since this is a higher moisture bean, your set-up (which includes the drying phase) should be longer to allow for more moisture to escape so that the maillard reaction can be more… “pure.”
I could say much more, and here are some places I have!
David
