Got a Hottop-B, an Omega HH506RA and couple thermocouples recently and started experimenting with this baby. I'm no expert roaster, taster or barista, but I think I found a roast profile for espresso that seems to work for many bean types. By posting this I'm hoping to get comments on possible improvements to this profile.

Thermocouples:

The environment tc is placed around the center of the hottop drum without touching the rod. The bean tc is placed about 1cm away from the drum and ~1.5cm from the back wall of the roasting chamber; it's always in the bean mass.


The data:

225g coffee beans
F = fan speed (0=off, 4=max)
P = element power (0=off, 10=max)
red line = env tc temp (logged every 5 seconds)
brown line = bean tc temp (logged every 5 seconds)
blue line = temp reading from hottop's display (noted every minute)
time = logging starts from 25:00 and ends at ~13:40
beans dropped at 24:30.
total roasting time = 10:50
First crack period is highlighted in gray.
Second crack just started at ~13:40, beans dumped.

In this profile I tried to apply my understanding from reading the roasting threads on H-B. In case you're a n00b, like myself, please pay attention to: "no expert", "tried" and "understanding"

Gurus, any tips?

Some nice work on the TC placement and the logging. Your temperatures seem to be more accurate than the HT sensor's, however, it's good to see that the HT sensor is highly correlated, so that it's profiling can be made accurate.

The roast looks good in terms of keeping all the details in proper limits, but the proof is in the pudding. The HT is an excellent roaster, capable of roasting a coffee as well as a pro. So you can check if your profile is in the ballpark by ordering green and roasted from the wonderful vendors (hint, hint hint hint) selling both -- Paradise, Klatsh, Terroir, Metropolis and in part PT's and Intelly.

Wow, great graphs! I just started collecting data myself (http://blowery.org/2008/08/25/more-roasts/) and I'm working on getting a thermocouple into the bean mass. If you don't mind, it would help me a ton if you could elaborate a bit on which thermocouples you're using and how you have them mounted in the drum. I really like the looks of your setup.

Also check out www.EspressoMyEspresso.com. Randy G. has a page there detailing mounting a bean mass probe in a HotTop, complete with dimensions.

Jim, you have no idea how happy I am to see you reply to this thread! Your posts have been/are a constant source of knowledge and enjoyment, thanks!

another_jim wrote:the proof is in the pudding

True. Unfortunately, a combo of my "average" barista skills and my inability to taste minor differences limits how much I can assess if a roast profile was good or very good. What I'm hoping to get by posting this is a form of a "standard, catch-all," profile I can trust to get a very good, but not necessarily magnificent, roast while I work on my other skills.

another_jim wrote:So you can check if your profile is in the ballpark by ordering green and roasted from the wonderful vendors

I'm not in the US, and my roaster options are very limited. I must fix the profile half blind

another_jim wrote:The roast looks good in terms of keeping all the details in proper limits

I was basically trying to follow your advice in other threads:

part#1 drying, upto 300F, between 3-5 minutes
part#2 300F to FC, ASAP
part#3 FC to dump, in 5 minutes, or to taste

I might have not understood your posts correctly but how about:
A. Extending part#3? And what's better, achieving that thru reducing power or increasing fan speed?
B. Dropping the beans in at a higher ET?
C. Eliminating part#0, the 1st 30 seconds of high fan, low power that I use to "wake up" the beans?
D. Things I didn't even consider?

blowery wrote:If you don't mind, it would help me a ton if you could elaborate a bit on which thermocouples you're using and how you have them mounted in the drum.

cafeIKE wrote:Also check out http://www.EspressoMyEspresso.com. Randy G. has a page there detailing mounting a bean mass probe in a HotTop, complete with dimensions.

Exactly! Randy's instructions are a great resource. This is the page. The TCs I used were Omega TTSS-HH.

coffee.me wrote:Exactly! Randy's instructions are a great resource. This is the page. The TCs I used were Omega TTSS-HH.

Excellent, that's what I have on order. From the photograph,it appears that your's are bent into position. I didn't realize you could bend the thermocouple... Neat!

hi...i tried your profile this am on 225 grams of test beans...these closely mimic the response i get with sm monkey which is my bean of choice......i got very close to identical numbers as you re. temp vs time with the hot top model b temp gauge...it appears u reached 1st crack in 8 min 20 sec at about 375 degrees indicated...i reached 1st in about 11 minutes at 395 degrees indicated...this temp is very close to my experience which is 397 to 400 to fc depending on how dirty the rear filter is...i let mine run for 18 minutes at which time indicated temp was 397...it never reached 2nd crack...i can not explain the differences...as the young kids say these days "go figure"

coffee-me wrote:I was basically trying to follow your advice in other threads:

part#1 drying, upto 300F, between 3-5 minutes
part#2 300F to FC, ASAP
part#3 FC to dump, in 5 minutes, or to taste

I might have not understood your posts correctly but how about:
A. Extending part#3? And what's better, achieving that thru reducing power or increasing fan speed?
B. Dropping the beans in at a higher ET?
C. Eliminating part#0, the 1st 30 seconds of high fan, low power that I use to "wake up" the beans?
D. Things I didn't even consider?

I'm not sure I can help you on these question, since they seem, to be more about the fine points of using the Hottop. The other people commenting are much better positioned to help you on these.

In general, the strength of your profile is getting a faster roast out of the Hottop than the out-of-the-box profiles. The HT is a very good roaster, but it had one knock. Some people, especially pros evaluating it as a sample roaster, thought it took too long and produced slightly flat tasting results. Your roasts should be a more vivid. If they turn out to be a little too light bodied, a little too intensely bitter or acidic as opposed to sweet, you can always slow back down.

Thanks for your comments, Jim.

Here's another one. The objective of this one was to use minimal fan AND extend part#3 a little bit:

225g coffee beans
time = logging starts from 25:00 and ends at ~11:50
beans dropped at 24:30.
total roasting time = 12:40
Second crack just started at ~11:50, beans dumped.

rlmerriam wrote:i can not explain the differences...as the young kids say these days "go figure"

The experts here could probably have better info to add. Here are my guesses: (1) if you don't have the the B or P model, voltage can have an affect. (2) room temp too cold/too much air circulating around the roaster? Sorry, I'm just guessing!

hi and thanks for the reply...my voltage is monitored and controlled by variac at 125 volts...the room is in part of a barn that is about 70 degrees in am when i do all roasting...i haVE A HOT TOP MODEL B...i have learned that indicated temperature seems to vary depending on how fast or slow the temp is rising so that may be a factor...also my beans may differ quite a lot from those used in your profile...in my experience i can not get to first crack in 8 minutes unless i add beans at 250 degrees instead of recommended 165 degrees...and then i have to use fan a lot less than i would like to....i was very interested in your profile because u reached 1 st crack in 8 - 9 minutes and seemed to add beans at 165 or thereabouts...i was disappointed when i could not duplicate your results.. anyway i'm gonna try less beans.. maybe 150 grams or so and see what happens...by the way...i tried to install temp probe and bent it so much that i broke it...it was a wireless device from oregon scientific