I got my custom thermos and did a quick few batches today, and have some artisan charts. Will look forward to cupping these and pulling some shots

All three batches were using 180g Brazil Sul de Minas -Antonio Microlotfrom sweet marias

The first one was probably the darkest. I pre-heated the BT to about 375 and then charged, the temp jammed right up, this was a pretty fast roast. 2nd crack seemed to bleed in from 1st crack, it was underway as I dropped, so this batch was probably a vienna.





The second one I charged almost immediately which was likely a mistake. The MET has this long decline and took awhile to get to the point where it was rising, and as a result the roast was a lot longer. I had it in my had that a slow RoR is good, but remembered I really don't know what I'm talking about. I got the temp to where the ET was rising, and then the RoR was probably too fast. 2nd crack had definitely started with this one, but only a bit. I mainly heard it after the beans had dropped and I was putting the tray in the cooling compartment.



For this one, I wanted to make sure the heat was ok and rising before I dropped the beans. I got freaked out that the BT was rising too fast, so cut the amps way down and turned the fan on to 3 or so...then I got freaked out that the ET was dropping so amped it up again. I made a point of trying to drop before 2nd crack, and pretty sure this is a FC roast.

• -- The ET is really MET...I think. I put that smaller thermo in the MET slot in the EricS documentation

• -- I'll need to read up on what a good RoR is. There is a book by Scott Rao(??) that explains a lot of that? Will need to check that out.

• -- What is the advantage of DeltaBT? (and wasn't able to get artisan to display it in chart)

• --Need to read up on what a good starting profile is...but will look forward to cupping these and seeing how they taste.

Had a chance to taste these side by side. (also uploaded better graphs)

The first darker one was a lot of husky dark choclolate and not much else. Just too dark. I don't hate this type of roast, kind of nice in cappuccino, but not really a success. Also, the roast I think was way too fast. The ET did stay consistent on this one as it did not in the next two, and I think the roast was just too fast.


The second was better, a little more complexity and sweeter into the milk chocolate range. Also a thicker mouthfeel. But still some husky darkness, a little burnt char which I didn't love.

The last one was the best, although I think I can get a much better taste out of this bean. This one had the most complexity, and a little fruit in the black currant range.


For the next roasts, I think I want to heat up more at the charge, maintain high temp into 1st crack and then progressively drop temp and kill the roast just prior to 2nd crack. Is that a good strategy?

A couple other Q's:

- what can I learn, and what should I be looking for in Delta BT?
- What should I shoot for in terms of consistency in terms of ET? (I am using the EricS thermos, and I have the Max ET type setup)
- based on these graphs, what is the best next step?

thanks!

I would say first roast too fast
2nd and 3rd have a real sagging in ROR that would lead to baked flavours

My recipe works well for me
(Note: my drum is painted flat black with bbq paint to aid power absorption. Also have ring of holes drilled around the back end)

Fan 5
Power 10
Preheat to BT 410
Charge 180-250g
Power zero
At turning point, power 10
When ROR peaks, bleed power bit by bit
Maintain slowly decreasing ROR
Near start 1crack prepare to cut power as low as 5 to avoid bump in ROR
Keep ROR steadily decreasing (no bump)
A bit after start 1c, Put power back to 10 to avoid a ROR crash
If energy runs out of ROR, drop (will taste great even if a bit light)
Otherwise drop when hit temp want

This works for me for light, medium and darker roasts, and for wet and dry process beans.

The keys are lots of energy at start and energy manipulation to have decent dry time and steadily decreasing ROR with no sags or bumps or crashes.

the third batch made for a very nice SO shot, a tight ristretto that could even have dropped a little sooner. The 2nd batch choked my silvia, so I need to dial that in, but suspect it will be too dark. I think that third batch is a decent starting point. Was thinking I would like to coax a little more sweetness out of this bean if possible.