Behmor

[Dragunov21]

IMO, yeah/

[fg1972]

I'm wondering if any instrumentation people have thought about turning the whole basket into a temp gauge. This might sound insane cos I'm just guessing here. But from what I read, the way the probes work is by measuring the difference of conductivity between the 2 cables that join at the end .. So why can't you measure that on the basket?

To go to all that trouble and then measure the cage is pretty pointless in my opinion.
If you've come up with a mechanism to obtain a reading from a rotating drum, why would you want to measure anything but the beans?

Right. So what are saying is pointing the ir temp gauge at the cage should be sufficient

What he is saying is that by pointing the IR at the cage, it will be pretty much looking through the mesh mostly seeing and
mesuring beans as the thin spokes passing by the IR probably won't effect the reading too much because the spokes surface area is tiny
compared to the surface area of the bean mass.

[fruity]

Right. So what are saying is pointing the ir temp gauge at the cage should be sufficient

I reckon it would. But getting a cost-effective IR probe into the Behmor that can survive the internal temp is a challenge.

[thegoner]

Wouldn't it be better for everyone to have the same setup for ease of comparison? It doesn't really matter if you can pinpoint the bean temperature to 0.02degrees, if your readings are 10 degrees different to everyone else. It hampers sharing the roast profile, and allowing others to replicate it.

What does matter is being able to repeat previous results. The exact numbers don't matter. Moving the probe to another location is not going to change the actual temperatures during the roast, it will only make countless previous roast logs irrevalent, and make it hard to share with others. I'm all for perfection and precision, but I think if everyone kept to the generally agreed 'best practice' spot, it would only add to the home roasting hobby.

[Dragunov21]

Wouldn't it be better for everyone to have the same setup for ease of comparison? It doesn't really matter if you can pinpoint the bean temperature to 0.02degrees, if your readings are 10 degrees different to everyone else. It hampers sharing the roast profile, and allowing others to replicate it.

What does matter is being able to repeat previous results. The exact numbers don't matter. Moving the probe to another location is not going to change the actual temperatures during the roast, it will only make countless previous roast logs irrevalent, and make it hard to share with others. I'm all for perfection and precision, but I think if everyone kept to the generally agreed 'best practice' spot, it would only add to the home roasting hobby.

The Behmor is simply not a universally-repeatable precision device; like it or not you (anyone, not you) are going to have to do your own tweaking/refining.

Ambient temperature off by 5°? Your roast will change.
Humidity? I'm not certain, but I suspect it would make a difference.
Voltage? Anecdotally, there can be a substantial difference.

You're never going to be able to get a roast profile off the net for a given bean and replicate the results/quality without work. As far as I'm concerned, the point of datalogging a Behmor is for your own reference (ie comparing roasts with reasonably similar variables) rather than sharing exact roast profiles.

I think it's important that people do their own work when it comes to stuff like this, because just like pulling shots, you'll generally get a better result if you try and gain an understanding of the process rather than just looking for an optimal set of settings to plug in without giving it further thought.

[Javaphile]

It's been said before and it looks like it's time to say it again.

The thermocouples that the vast majority of folks here use have an error rate of +/- 2%. That's 2 percent, not 2 degrees. While you can repeat one of your profiles with incredible accuracy the same can not be said for exactly reproducing someone elses roast by precisely following their profile. 200C on one persons thermocouple could be anywhere from 196C up too 204C on someone elses.

The best way to accurately reproduce someone elses profile is to follow the shape of the temp curve while trying to hit the various markers (First crack, rolling first crack, second crack etc) at the same time as the original profile.


Java "Don't get caught up on your crack temps being different from others." phile

[fruity]

Behmor

The best way to accurately reproduce someone elses profile is to follow the shape of the temp curve while trying to hit the various markers (First crack, rolling first crack, second crack etc) at the same time as the original profile.


Java "Don't get caught up on your crack temps being different from others." phile

*of course that will only work if your probe is in the same place as the owner of the profile you're trying to replicate. ;-)

There is a vast difference in probe readouts depending on location, so make sure you've got one in EXACTLY the same location if you're trying to copy another's profile.

[Dragunov21]

Do you have any quantitative definition of "vast" here?

That method will still be the most accurate, and the curve should appear quite similar irrespective of minor variations in location. If you're comparing a bean mass measurement with an air/chamber temp measurement that's a different story...

[Vinitasse]

Do you have any quantitative definition of "vast" here?

That method will still be the most accurate, and the curve should appear quite similar irrespective of minor variations in location. If you're comparing a bean mass measurement with an air/chamber temp measurement that's a different story...

Just curious... do you own a Behmor, or ever roasted with one?

[fruity]

Do you have any quantitative definition of "vast" here?

That method will still be the most accurate, and the curve should appear quite similar irrespective of minor variations in location. If you're comparing a bean mass measurement with an air/chamber temp measurement that's a different story...

Sure, vast = over 100°C difference. This is the measured difference between two probes in my Behmor during the same roast.

As I said, you absolutely must be comparing the same location for your probe(s) or trying to match another profile is already a lost cause.

[Dragunov21]

Damn, where were the probes? I'd have thought that as long as they were away from the elements the readings would be reasonably similar. Cheers.

[fruity]

Damn, where were the probes? I'd have thought that as long as they were away from the elements the readings would be reasonably similar. Cheers.

Currently in the coffeesnobs recommended spot (top left, back of chamber) and one under tray. But even putting a probe next to the left cage hook as opposed to an inch or so higher (or lower) gives you at least a 30°C variation.

The airflow in the chamber seems to make a huge difference to probe readings. Proximity to chamber walls is also a factor, I think. I find the one under the chaff tray to be the most stable /predictable.

[Dragunov21]

Cheers. Is there much airflow in the chamber during a roast? I'd always assumed the fan was running to circulate air but I've never actually taken notice.

[fruity]

Cheers. Is there much airflow in the chamber during a roast? I'd always assumed the fan was running to circulate air but I've never actually taken notice.

There seems to be quite a bit. I guess you'd need some coloured smoke experiments to see just how much.

[jbjabiru]

Hi all, had my Behmor for 2months and done 7 roasts, finding 220g roasts on 1/2lb settings work best. 1lb roasts seem to have a push to get 2nd crack. But then again, I'm a newbie..