Rate of Rise after Dry End

-

A friend asked what range of RoR I get after the first "Drying" phase of the roast. It's mostly between 10ºC/min and 4ºC/min, with a slight 'bulge' when the beans start to crack and heat escapes from the 'pressure cooker' hot cells that burst open. 

When that bulge happens (around 10mins here) the probe gets hotter but the expanding and bursting bean cells themselves do not get so much hotter. It's like lifting the spout off a hot kettle. You suddenly feel extra heat on your finger tips but that does not mean the kettle just suddenly got hotter.



Reacties

Chris zei…
I liked your comment about the RoR bulge and what it actually is indicating... only a reference about the thermocouple's quick response to the relatively short steam release during 1st crack. The beans on the other hand never respond so fast. Until now, they've needed many minutes to get up to temperature, and are much slower at taking on heat at this point. I don't get overly concerned with it. I picture an imaginary connecting line from where the bulge starts to where it ends and stabilizes... to me, this shows the true RoR trend and how the environment actually affected the beans. :)
3 februari 2023 om 07:08
Frans zei…
Exactly! I agree with your 'imaginary connecting line' idea.

In the approach to the FC I gradually lower the heater energy & increase airflow. Some of the bean energy release is absorbed by the bean mass which compensates this.

Some who do not understand the FC energy 'puff' quickly lower energy as soon as they see the 'bulge' and next they are struggling to deal with the sudden crash of RoR after the 'steam exhale' moment has passed just as their lowering of energy or increase of cool air inflow is taking effect.

3 februari 2023 om 07:15
Een reactie posten

Populaire posts van deze blog

Finished Pavoni & Fuji PXG4 pid: Probe Inside the Ring

-
Afbeelding
Delicious cup: all the work was well invested! At the end of the previous blog about the pressostat and PID working together , I mentioned that I would like to clean up the xmas tree of wires and have as few cables and probes as possible to visually disturb the classic design of the La Pavoni. Getting rid of the probe that was fastened with copper tape to the top of the brew group was a priority. I wanted to hide a new probe in the cooling fin as close as possible to the brew group. This morning I asked Tije if he could do that. He would need to drill a straight hole of 3mm diameter in the 4mm inner ring of the cooling fin that sits as a tight clamp around the brew group. Always the optimist, Tije set to work: First, Tije made a piece of aluminum to fit the inside of the ring. Drilling a thin hole straight through the curved aluminum, if possible tangentially going through the inside of the ring to touch the brew head directly, you need the support of the temporary insid...
Meer lezen

KiwiSDR2 [radio]

-
Afbeelding
  Despite selling one and giving away two of the five monster vintage 'boat anchor' receivers that I had, I still enjoy listening to shartwave radio. The modern iCOM R8600 that I also have has a wider range plus some decoding options but it's not easy to figure out what encoding is used on which frequencies. The SDR-Control app from Marcus Roskosch at https://ham-radio-apps.com/ makes this much easier and also allows some remote control of the receiver so you can place it and an antenna at the top floor of your house while listening downstairs. I also got the SDRplay RSP1B box: This offers a great listening experience at a very low price compared to the iCOM hardware. I had one before and bought one again after a (somewhat limited) Mac version of the software became available. This device needs a computer to be connected to the receiver. For some time now a nifty little device has appeared which not only works standalone, it even allows you or anyone else to utilize the ...
Meer lezen

Tiny Cheap Fluid Bed Roaster by Tije and Jan

-
Afbeelding
(also see Daily Coffee News feature ) Tije designed and made the following structure for a tiny and cheap fluid bed roaster, to which Jan van der Weel added the Arduino parts, electronics and programming: Sketch by Tije de Jong Jan sourced a very cheap blower (€ 11) to start with, Tije developed and constructed the mechanics, Jan built together and programmed the TC4 / SSR electronics.  On his blog, Jan will specify exactly how the TC4 part is combined and programmed and I will copy these details into this blog entry, just as Jan will use this video in his blog. We did a few test roasts to make sure it works at all and it does. Towards the end, the first roast tended to get a flat BT line and airflow was slightly decreased. 200g seems max load of green beans. Second roast a little more power was given to the heater. Next we will try the Background Roast driven by the PID software of Artisan. A week later, with updated software that works better to change the...
Meer lezen