Hi everyone, if I’m reading this chart correctly, it looks like the bean temp starts at 200 deg, drops to approx 100 deg and rises again. This is not my understanding of how this works (the beans go into the bullet @ room temp and rise) Also, the IBS Drum temp starts at zero and rises .I always thought that this should be the other way around. I know I’m misreading something but hopefully someone can tell me my misunderstanding. Thanks -Paul
@pmahon1998.nTac The blue line is the bean probe temp. Those readings are just an artifact of the physical nature of the bean probe. Because of its mass, the reading it provides lags behind the actual surrounding temperature.
In broad steps:
- You preheat the roaster, which takes 10-20 minutes. The bean probe has had plenty of time to catch up to the air temp in the roaster, so it reads 200C.
- You drop a large mass of room-temperature beans into the roaster, which causes the bean probe to lose heat for about a minute as its temperature converges with the temperature of the beans-- the beans rise in temp for the first minute as the bean probe falls, and the two meet in the middle somewhere at about 1 minute. The blue line begins to move up: this is called the turning point.
- As you continue to apply heat, the beans and the bean probe continue to rise in temp.
The lighter of the two purple lines is the temp from the infrared (IBTS) sensor, which doesn’t have this same thermal inertia. It’s designed to read the surface temp of the beans, and you can see it starts at about 25C and continues to climb.
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