Maxwell -

Your latest profile looks a lot like what I measure on my Hottop. I wish I could also say "that's a good profile," but I, too, am still experimenting. I can say that this particular batch of coffee came out very, very good. But I have used similar profiles on other coffees, even on different crops of this same coffee, and not always had the same good outcome.

Jim

*no Hottop experience*
I see Maxwell's turnaround point was 125f which generally seems a bit low? Are you both using the same batch size?

farmroast wrote:*no Hottop experience*
I see Maxwell's turnaround point was 125f which generally seems a bit low? Are you both using the same batch size?

I noticed that, too, but thought it might be a function of sensor configuration. It's a good question to try and answer, though.

I vary the batch size from 225g to 250g, usually closer to the former.

Jim

Yep, amounts are either 225 or 250, and turning point tends to be right at 130, regardless of bean--could certainly be a probe placement issue, as I had thought that your turning point seemed on the high side!

Ive been playing around with few of the profiles on here. the results have been less than desirable. here's the notes from my last roast:

kenya aa kirinyaga 150g

heat: 6 fan: 4
6:25 - heat: 10 fan: 4 - 295
9:00 - heat 5 fan: 0 - 360
10:10 - first crack - 394
10:30 - first crack rolling - 400
12:30 - end of first crack
13:45 - end roast - 430

I was going for city+ but it turned out a bit darker. I pressed some 24 hours after...not so great. very subtle notes but mainly smokey/ashy.

im using an omega hh506ra with the bead going down through the chute. it's swinging around which leads me to believe I'm not getting a very accurate reading. I also have the 6" probe that I would like to install but I'm having trouble getting the holes drilled.

kevin, looks like you're trying to apply the last two profiles I posted (1, 2). I don't know your bean but it took 6:25 to get to 295F BT which is longer than what you see on mine. You could try P7 for the first leg and see if you can get to 300F BT in 5:00 or so and see if you like the results better.

Another thing, at 360F you reduced to P5, I found that to be too fast(on my setup, beans, etc) for managing the last leg of the roast. However, P4 could drop your ET! IMHO, an ET probe is a must if you're into experimenting with profiles.

Last thing: get comfortable with your roaster's P&F levels & thermometry by playing around with a few lbs of cheap beans. Oh, and read this .

coffee.me wrote:kevin, looks like you're trying to apply the last two profiles I posted (1, 2). I don't know your bean but it took 6:25 to get to 295F BT which is longer than what you see on mine. You could try P7 for the first leg and see if you can get to 300F BT in 5:00 or so and see if you like the results better.

Yes, I was trying to base my roasts off those 2 profiles. I tried Randy's before along with some of your other profiles.

coffee.me wrote:Another thing, at 360F you reduced to P5, I found that to be too fast(on my setup, beans, etc) for managing the last leg of the roast. However, P4 could drop your ET! IMHO, an ET probe is a must if you're into experimenting with profiles.

I thought you killed the fan at 360 then went between 4&5 on the heat til the end of the roast?

coffee.me wrote:Last thing: get comfortable with your roaster's P&F levels & thermometry by playing around with a few lbs of cheap beans. Oh, and read this .

Ive been playing around with some beans that have been sitting around for about 2 years. They are far less temperamental, and look decent.

This last roast seemed to be doing well until my probe slipped into the drum just at 1C.

Ethiopia Bonko Wet Process - 150g

P:7 F:4
2:00 - H:7 F:4 - 170
5:00 - H:8 F:4 - 273
6:20 - H:10 F:4 - 300
8:16 - H:5 F:1 - 360
9:14 - H:5 F:1 - 370 - 1C
10:40 - H:5 F:1 - 395 - 1C Ends
11:45 - End Roast - 403

These temperatures are from a 6inch omega probe in the bean mass.

- Why is first crack starting and ending at such a low temperature?
- When I ended the roast at 403 degrees that should just be around first crack, right?
- I was aiming for city - city+ but when comparing this roast to sweet maria's chart mine are a lot darker. also there is quite a bit of chaff.
- Could my thermometer (omega hh506ra) need calibrated? Don't they ship calibrated?

Can I suggest you solve the issues you're having with your thermometry before proceeding further?

Randy's & this forum have examples of the probes in place, seen them yet? what's stopping you from fixing that?

As for calibrating the meter, yes you can and the instructions are there in the meter manual. To check current state of calibration, you could dip the probes in an ice slush or condensed steam; but I suggest you search this site for the proper instructions for doing that.

kevin wrote:This last roast seemed to be doing well until my probe slipped into the drum just at 1C.

Not sure what you mean. Do you have it mounted through the chute cover like Randy's?

kevin wrote:These temperatures are from a 6inch omega probe in the bean mass.

There may be small differences in the readings from a "grounded" vs "ungrounded" vs "exposed bead" probes. Which style do you have?

kevin wrote:- Why is first crack starting and ending at such a low temperature?
- When I ended the roast at 403 degrees that should just be around first crack, right?
- I was aiming for city - city+ but when comparing this roast to sweet maria's chart mine are a lot darker. also there is quite a bit of chaff.
- Could my thermometer (omega hh506ra) need calibrated? Don't they ship calibrated?

First, if this is a new meter, I doubt very much that it is out of calibration. Calibrating the meter itself is not generally something you can do with things lying around the house (i.e. millivolt source, reference thermocouple).

More likely, I think, are "stem effects" with the probe. With such a light bean load (150g), not very much of the tip is going to be submerged in the bean mass. This allows the reading to be affected by conduction of heat away from the tip by the metal in the rest of the probe.

To get a very rough idea of the calibration of your meter/probe, fill up a container with ice, then pour in enough water so that the mixture can be stirred. Let it sit 10 minutes, then measure the temperature by submerging as much of the probe as possible into the mixture. This is should be within ~1 degree of 32F, and is a lot easier to make than the better, and more accurate ice slush that coffee.me suggested.

Jim

coffee.me wrote:Can I suggest you solve the issues you're having with your thermometry before proceeding further?

Randy's & this forum have examples of the probes in place, seen them yet? what's stopping you from fixing that?

As for calibrating the meter, yes you can and the instructions are there in the meter manual. To check current state of calibration, you could dip the probes in an ice slush or condensed steam; but I suggest you search this site for the proper instructions for doing that.

I've tested the probe with a ice bath, and it's on point at 32 degrees.

I followed Randy's instructions on installing the probe. Im using the setup he suggests: omega hh506ra with the ktss-hh probe. i also have the wire bead thermocouples that came with it.

First off- thanks for the insightful thread here guys. I've been reading more and more here lately as I'm a new HTB owner, and the leads from this thread alone will keep me busy for a while.

kevin wrote:I've tested the probe with a ice bath, and it's on point at 32 degrees.

Can I suggest you test the probe in water that's at a rolling boil instead? That's closer to the temperature range you care about, and it may or may not be as accurate as it was at the lower temperatures. Factor in altitude and barometric pressure if you want to be super accurate...