I’m trying to determine if I may have a voltage/amp problem, a roaster problem, or [other]
As long as I’ve had my bullet v1.5 (~4+ years?) I’ve found that power settings less than P4, on a 500-600g batch will inevitably stall the roast. Originally I assumed it was an issue with the roaster being unable to draw the necessary power from the line so I had a dedicated 120v 20amp circuit installed that is for exclusive use of the roaster, however nothing has changed since the upgrade.
I hit this again today while I was experimenting with a recipe that called for a drop to P1 in the final few degrees of a City roast.
Recipe was Aillio Bullet Filter Coffee Profile «third wave»
The roast:
What I’m trying to figure out is: I see plenty of profiles that involve sub-P4 power, at higher charge sizes than I’m using and I’m trying to figure out what might be different in my case.
I’d expect to see a drop in RoR following first crack for the usual reasons, but there seems to be more to it in this case as following supposedly well-tested recipes with a lower charge size produces divergent behavior.
Electrical knowledge is nowhere near an area of competency for me, so I’m curious if this looks familiar to anybody who may have experienced something similar.
Here’s my guess. These recipes have been on the site for a while now, while the bullet had multiple firmware updates that gave it even more power. What I think, but you may write a mail to Ingo from Roast Rebels, who is a very nice and helpful guy, is that aiming for 9% development they were going for FC near 8:30 to 9 minute mark, while yours gets there in 7:10 and you have 22% development. I’m probably wrong, but something must justify the 13% difference in development. That’s the thing about recipes and maybe not identical firmwares, different ambient conditions, IBTS cleaning etc. Also, with previous firmwares, the PH seemed to go higher, so maybe his 250 is now 260. What I think would be best is to ask the one who made the recipe for timing of FC, yellowing, starting BT just before the drop and so on. That way you will know the differences between the two and may adjust the recipe to your machine and your surroundings. Only then you might look for other machine or power related problems, which I don’t think you have. If anything, yours seems to run through the roast and may not have problems with P1 on higher PH or some other modification to the recipe.