Cormorant BT and ET Probes

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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LBIespresso
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#1: Post by LBIespresso »

I have read through all of the Cormorant posts here at least once as well as the Cormorant FB group. It seems to me that the most recommended digital BT and ET probes are the Mill City 2mm. I do not plan on batch sizes outside of the 300-600 range so hopefully I will not need to do any of the probe bending that others have to accommodate small batch size.

I got the following email from Johan, "...If you have any thread requirements, please let me know.
I usually put the BT probe right next to the analog BT probe and the ET probe usually goes into the handle so it sits above the drum, I find these positions work well, but if you have another suggestion, I'll happily place them there..."

My questions are:

1. Do those seem like the best spots for BT and ET?
2. By thread requirements does he mean something like "M8x1.25" (like it says on the MC website)?
3. The MC probes come in 50, 75 and 100 MM. Which size is recommended for BT and for ET?
4. Is there anything else that I should be telling or asking Johan about the probes?

I know some of this information is in all of the reading that I have done here but it would be nice for me and hopefully for others to have it all in one place. Thanks in advance for any input!
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sosha
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#2: Post by sosha »

I just emailed Johan about this. Will share his response here.
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sosha
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#3: Post by sosha »

I sent him a link to the Mill City thermocouples. He suggests the 50mm for BT, and the 75mm for ET, in the positions you describe. He'll drill 24mm holes for them (this is a change).

I'm going to go with the positions he suggests in the email (same as in your response), because I have ZERO experience with this roaster, which he knows intimately.
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LBIespresso (original poster)
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#4: Post by LBIespresso (original poster) replying to sosha »

Hey Patty. Check the FB group as there is a long thread on there about all of this at the top. Too cumbersome to try and put it all here and I don't want to post the same thing in 2 places.
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JohnB.
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#5: Post by JohnB. »

I tried the lift handle position for the ET but found the readings much too high to be of use. Might be a good spot for a 3rd Max ET probe if you want to now how hot it gets at the top of the roaster above the drum but I want to know how hot it is getting inside the drum, above the coffee. As I posted previously I've found the lower bean chute screw hole to give the most useful ET readings. The reason I bend the ET probe up at a 45* angle is to get a reading well above where the beans might contact the probe.
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LBIespresso (original poster)
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#6: Post by LBIespresso (original poster) replying to JohnB. »

Since you have infinite more roasts under your belt than I do ( x/0 = ∞) I appreciate the input. That said, my understanding is that BT is the most important and ET is a good measure of energy put into the system. Are you saying that the data from a probe above the drum will be less effective at communicating this? This is all so hard conceptually without having roasted yet. I do appreciate hearing all of these opinions even if so many are conflicting!

Thanks!
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JohnB.
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#7: Post by JohnB. »

What I'm saying is that the temp of the air actually hitting the beans is more important to me then the air temp at the top of the roaster above the drum that the beans won't see.

Johan builds a nice roaster but I haven't been crazy about his choices for probe placement. Summer 2018 when I was considering the purchase the Cormorant V1 Bt digital probe was located above the analog probe. I asked Johan how this would work with smaller (300g-400g) loads. He agreed to run some tests & found that having the digital probe below the analog probe was a better idea. This change was incorporated in all the V2 (10/18 on) roasters. My roaster came with the ET digital mount in the side of the bean chute above the drum. This placement gave readings below BT & were useless IMO. I tried the rear handle placement & found the readings to high so I ended up in the lower chute mount screw hole where the probe is located inside the drum above the beans.
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sosha
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#8: Post by sosha »

So, now, I'm confused.

John, if you were in my shoes, where would you ask to have the probes installed/holes drilled?

Patty
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JohnB.
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#9: Post by JohnB. replying to sosha »


The current digital BT probe location is fine. Talk to Johan about mounting the ET probe in the bean chute bottom screw hole. Also tell him you plan to use 2mm probes if you are going with the Mill City T/Cs that many of us use. Alternately you can opt out of having him set up the ET location & just center drill the mounting screw & mount the probe through the screw which is what I did.
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LBIespresso (original poster)
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#10: Post by LBIespresso (original poster) »

sosha wrote:So, now, I'm confused.

John, if you were in my shoes, where would you ask to have the probes installed/holes drilled?

Patty
Thanks John for your input on this. I'm with Patty...waiting on your advice!
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