Roasters-Different Roasting Equipment

bcspark

Firstly I would like to attest to the simplistic roasting on my modified KKTO . Roasts roll out,600-1000 grm batches are the prefered weights and are roasted by profile ,sound and smell.But for my personal use ,as I am a one person household and morning coffee only, I was given a Hot Top B with added bean mass probe as a birthday present from my family. Had some trouble coming to terms with a drum roaster with a set program pre installed and a K type probe reading the air temp. on the display.This air temp has full control over the roast duration and a maximum of 220deg when reached ejected the beans.Time on the display ranged from 0-25 minutes but never controlled the roast.Had quite some difficulty reaching 2ndC because air temp and bean temp were up to 20deg different with the latter being the lower so my preferred roast of 200deg could not be achieved .After much research and deliberations I applied my profile roasting experience by using bean temp as my base and controlling heat and fan to achieve 1stC at 174deg and 2ndC at 194deg ,approximately, on a 400grm roast.Timing is set at 24mins and and counts down and has a duration of 20mins to eject to a beautiful cs8 roast at 2ndC.I now have a documented profile of time,fan and heat to achieve my desired result for my personal satisfaction.

Brett H

Great stuff BC! I have a Behmor that I've not used in more than 12 months because I like my KKTO so much.  I think any new roaster has a learning-curve all its own and it sounds like you're 'all over' the hot top.  Be interesting to hear if anyone has something a little less conventional....

mycuppa

Generally speaking, for a drum roaster using direct heat source the air temp needs to be at least 20 Deg C above the bean temp in order to maintain thermal momentum. In the earlier stages of the roast, that differential needs to be greater. This concept applies for most of the smaller drum roasters from Probat, Geisen, Has Garanti, Proaster, etc. where the heat is applied in close proximity to the drum - either a controlled distance or via the deflector shield. Drum roasters using indirect heat source, e.g. oven or hot-box, etc. are in effect air roasting and this type of roasting requires a much higher air temperature, e.g. 400 - 500 Deg C. Of course, all this depends upon thermocouple placements, etc. and the individual design of the roasting platform. Without knowing anything about your HotTop, it would be interesting to target a 13 - 15 minute roast and see what difference you discover. This may require a reduction of batch size in order to reach those targets. It may also be impossible due to inadequate power. If your roaster principally uses convection rather than conduction, the general rule of thumb is shorter roast times for convection and longer roast times for conduction. The reasons these rules (and I use the word rule very loosely) seem to make sense is due to the way in which heat is transferred into the core of the bean. If you try shorter roast times with a higher level of conduction, you will risk scorching and tipping. If you try longer roast times using convection you risk baking. Finding the ideal range takes a lot of trial and error. Every roasting platform is different.

steve82

on 1432356642:

Generally speaking, for a drum roaster using direct heat source the air temp needs to be at least 20 Deg C above the bean temp in order to maintain thermal momentum. In the earlier stages of the roast, that differential needs to be greater. This concept applies for most of the smaller drum roasters from Probat, Geisen, Has Garanti, Proaster, etc. where the heat is applied in close proximity to the drum - either a controlled distance or via the deflector shield. Drum roasters using indirect heat source, e.g. oven or hot-box, etc. are in effect air roasting and this type of roasting requires a much higher air temperature, e.g. 400 - 500 Deg C. Of course, all this depends upon thermocouple placements, etc. and the individual design of the roasting platform. Without knowing anything about your HotTop, it would be interesting to target a 13 - 15 minute roast and see what difference you discover. This may require a reduction of batch size in order to reach those targets. It may also be impossible due to inadequate power. If your roaster principally uses convection rather than conduction, the general rule of thumb is shorter roast times for convection and longer roast times for conduction. The reasons these rules (and I use the word rule very loosely) seem to make sense is due to the way in which heat is transferred into the core of the bean. If you try shorter roast times with a higher level of conduction, you will risk scorching and tipping. If you try longer roast times using convection you risk baking. Finding the ideal range takes a lot of trial and error. Every roasting platform is different.

Great post, simple and concise guidelines that anyone starting out would do well to print  and stick on the wall. Yep LOADS of trial and error! Love my Quest M3 and would not have it any other way.

bcspark

on 1432356642:

Generally speaking, for a drum roaster using direct heat source the air temp needs to be at least 20 Deg C above the bean temp in order to maintain thermal momentum. In the earlier stages of the roast, that differential needs to be greater. This concept applies for most of the smaller drum roasters from Probat, Geisen, Has Garanti, Proaster, etc. where the heat is applied in close proximity to the drum - either a controlled distance or via the deflector shield. Drum roasters using indirect heat source, e.g. oven or hot-box, etc. are in effect air roasting and this type of roasting requires a much higher air temperature, e.g. 400 - 500 Deg C. Of course, all this depends upon thermocouple placements, etc. and the individual design of the roasting platform. Without knowing anything about your HotTop, it would be interesting to target a 13 - 15 minute roast and see what difference you discover. This may require a reduction of batch size in order to reach those targets. It may also be impossible due to inadequate power. If your roaster principally uses convection rather than conduction, the general rule of thumb is shorter roast times for convection and longer roast times for conduction. The reasons these rules (and I use the word rule very loosely) seem to make sense is due to the way in which heat is transferred into the core of the bean. If you try shorter roast times with a higher level of conduction, you will risk scorching and tipping. If you try longer roast times using convection you risk baking. Finding the ideal range takes a lot of trial and error. Every roasting platform is different.

I take onboard your expert advice with thanks . There are two factors influencing the roast profiles on HotTop one ,lack of heat power and two the preset air temp of 220deg then dump not adjustible . The roaster has a pre loaded program  that cannot be removed but only modified during roast .As a drum roaster it does not conform to the commercial concept only in the fact that another three programs can be installed . I hesitate to do this as no two bean varietes roast the same and ambient air temps vary also.

bcspark

Small story of family involvment. I replied to an invitation to visit my youngest son (50 years young) in Ipswich .Mick has two young sons and they showed interest in the roasting process. Sunday morning I with green beans , Baby roaster , portable camp stove & gas canisters drove to visit. After the welcoming cuppa we proceeded to weigh beans and load the Baby then applied heat and so the roast began with the usual advice the three sss sight smoke smell . Half way into first roast Mick took over and completed it and two more . Story ends with ,I lost a roaster ,stove and had to order from CS 7.5kg of greens.

Brett H

on 1432422487:

Small story of family involvment. I replied to an invitation to visit my youngest son (50 years young) in Ipswich .Mick has two young sons and they showed interest in the roasting process. Sunday morning I with green beans , Baby roaster , portable camp stove & gas canisters drove to visit. After the welcoming cuppa we proceeded to weigh beans and load the Baby then applied heat and so the roast began with the usual advice the three sss sight smoke smell . Half way into first roast Mick took over and completed it and two more . Story ends with ,I lost a roaster ,stove and had to order from CS 7.5kg of greens.

Fantastic outcome!!  That's what it's about.  Now sit back and wait for them to pay brown bean dividends

Koffee_Kosmo

On the HotTop specs they state that it has a capacity of 250 gr to 350 GD So your 200 gr trial should have been a breeze But as stated above - Any new equipment will require some trial and error and placed on L plate category for a while KK

Brett H

Reading your posts BC I reckon you're past L plates but KK is right about the new equipment learning-curve.  What is your voltage at the GPO??

bcspark

on 1432456073:

Reading your posts BC I reckon you're past L plates but KK is right about the new equipment learning-curve.  What is your voltage at the GPO??

Thank you Brett H for your vote of confidence . I am an old sparky and I do  not want to investigate the voltage supplied to a GPO in an aged care facility. What I don't know I dont have to worry about. Brett regardless there is no control over the delivered supply so I have to roast with what is supplied. To you KK you should know I like to stretch the boundaries . My first 200g roast was jut over first crack by using the preset program as the beans ejected at 220deg air temp . Took me a couple of throw away roasts to use the extra bean probe to roast by profile to reach my desired roast and beat the preset program.

bcspark

I have developed a table of the HottopB two probes,fan speed,heat applied and time.This gives me great flexability in my roasting,My batches of 300 to 350 grm can now be taken to 2nd or just into using a 20min time frame.This gives to me fresh beans for my daily trippleR.For my coffee addicted family bigger batches are required so to my modded KKTO I go.On the larger roaster I have no limits up to 1kg and as dark as I want to go.

Koffee_Kosmo

on 1436471245:

I have developed a table of the HottopB two probes,fan speed,heat applied and time.This gives me great flexability in my roasting,My batches of 300 to 350 grm can now be taken to 2nd or just into using a 20min time frame.This gives to me fresh beans for my daily trippleR.[size=12pt]For my coffee addicted family bigger batches are required so to my modded KKTO I go.On the larger roaster I have no limits up to 1kg and as dark as I want to go.[/size]

The batch size is one of the endearing features for the KKTO design Small to Large - I roasts them all KK

bcspark

Paul I have been roasting on a KKTO for a few years now and the only replacement has been the blue silicon seal under the TO.Testimonial to your design and kit I bought . Sorry have not kept track of number of roasts but on a average of 1.5 650grm roasts per week I will let you guess