BT thermocouple placement on Poppery I

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
cronus10
Posts: 24
Joined: 8 years ago

#1: Post by cronus10 »

Before I start drilling holes in my Poppery I, I'm curious about other people's opinion on the best location for a BT thermocouple. I've seen pictures where people have drilled a hole into the metal portion of the roast chamber. Is this the best location, or should it be higher in the chamber, in the bake lite portion of the chamber?

I plan to drill a small hole in the bottom portion of the metal where the heating element is for the ET probe placement.

Thanks!

robmatic
Posts: 58
Joined: 11 years ago

#2: Post by robmatic »

I drilled a hole in mine so that the tip of the thermocouple would be well submerged in the bean mass, but not touching any metal of the chamber and not in a direct path of airflow. I don't know what is "optimal", but getting the thermocouple to touch the beans is important, as this will give a pretty reasonable indication of bean temperature, and I got readings that were pretty consistent with well known numbers, ie, 394F or so for first crack, etc.

cronus10 (original poster)
Posts: 24
Joined: 8 years ago

#3: Post by cronus10 (original poster) »

I have a rigid threaded thermocouple from Auber I had planned to use for BT (http://www.auberins.com/index.php?main_ ... cts_id=109). Perhaps it would be better to mount this kind of probe in the plastic portion of the chamber so it doesn't pickup extra heat from the metal?

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Andy
Posts: 242
Joined: 14 years ago

#4: Post by Andy »

Mine is drilled through the plastic at about 45 degr, so the tip of the probe is just below the surface of a 150 g charge at rest. When the fan Is running the tip is well into the bean mass as the beans are lofted by the air flow. By the time the beans have expanded it is approximately in the center. 1c occurs at 400F, typically, and 2c at 440F. I have used both flexible and rigid probes.