Wanted to add my experience here as well, since similar to others, I had 9 months of a terrible time with the Bullet and now have great(amazing?) results. I used to have a Behmor where the same beans worked beautifully, whereas in the bullet I choked every morning on my espresso. A disgusting time I don’t want to look back.
The issue is that there are so many knobs on the Aillio and I had no systematic way to approach them and no theory behind me (I only saw this thread here now)
A lot was mentioned already, but wanted to summarize my approach here which took me from terrible to amazing:
- changed batch size from 500g to 350g ( I do 2 batches back to back now)
- changed preheat from the default 200C to 220C ( that has a tremendous impact). I also let it preheat for a longer time. I have no system as I do other stuff but it sometimes approaches 45-60min preheat time.
- rather than playing with power settings I mostly do fan speed. I adjust power ±1 at most during the roast but mostly keep it at P6
- I do a lot with fan speed - I used to have only F2 - but now do F4-5 as default and regulate up or down. If I feel temp change slows too much I lower the fan speed a little when temp rises too much I raise fan speed.
- There is actually impact from the drum speed. I have my default now at D6, not the D9 which I can test the difference
- Changed my beans. Lastly I changed my Ethopian batch which just didn’t work on the Aillio but was phenomenal on the Behmor.
I do only SingleOrigin and for 2 months have had amazing results with these adjustments with different beans SM-YEMEN, SM-Burundi, SM-Polar Expresso.
I didn’t see this thread, but what triggered most of my changes was a notion that I read I need to let the beans develop after yellowing. That’s for the most part what I do now. I have lots of momentum in up to yellow and then take a little out and even more so when it reaches first crack where I take all out ( lower power and increase fan ) and then push up again (higher power - lower fan) when then RoR goes below 5.
You guys are way more experienced. I only roast for 3 years overall and 2 only on the Behmor and have no theory behinf me, but the above really worked for me. Oh, the roast curves between terrible attempts and amazing ones are not that different in my opinion. When I look at mine anyways. There seem to be very subtle changes that make great coffee and really don’t show up in the graphs. ( to some degree they do by reaching a certain temp 30s earlier but it’s subtle)