KKTO Few months on

Re: KKTO Few months on

CS Member Borat 123 has had a pro modify his TO oven to take the ON/OFF thermostat out of the equation

He will be along soon to shed some more updated info on this over and above what he has already posted on another thread
http://coffeesnobs.com.au/YaBB.pl?num=1292925707

Thanks KK, and here I am....   

The mod I did was really aimed at increasing the batch size.   (It went from around 800gms to 1.2kg+)

One thing Ive noticed is that the KKTO temperature is best controlled with burping rather than playing with the temp control.   Due to the simmerstat controlling the TO element, turning the temp up or down has a lag, which is hard to predict.

The KKTO will however give excellent results by just turning the temp up to max, then burping at regular intervals to get the temp ramp where you want it.   By burping I mean just lifting the edge of the glass up an inch or so for a couple of seconds to periodically let some heat (and smoke) out.

Placement, type of thermocouple and the roast batch size also has an impact of controllability.   I use a K type probe from Jaycar, which runs down the inside of the pot, and is mounted about 1cm from the bottom.  If you do a bit of a search, Ive posted a few pics of this setup previously.

If your temp ramp increases and decreases very quickly, and is almost impossible to control, its likely just measuring air temp.  You need a batch size that covers the probe properly and that will give you a reading that is closer to actual bean mass temp.    On my unmodded KKTO, that was around the 750gm mark, but again this depends on where your probe is positioned.    Larger batch sizes in the KKTO are IMO much easier to control.....

And lastly, dont be afraid of Looong Sloooow roasts.  The KKTO will really draw out the SO characteristics of the bean, if you purposely use nice gentle temp ramps of say 15C/min up to 160, then around 8/min slowly decreasing to a max of 2/min between first and second crack.   20min roast time is a good thing.

I also use a pre heat of the roaster to get the metal temps even, then pre heat the beans at around 50-60 for five mins to get the moisture content and bean temp even prior to roasting.   This is more critical with the larger roasts.  The combination of the pre-heat, gradual temp ramp, and very low ramp between 1C-2C is good insurance to avoid tipping.  I used to curse those little black divots when I first started roasting.... >

[Koffee_Kosmo]

Re: KKTO Few months on

Cheers both - cant think of any simple options I can play with.  KK do you still follow the same process on yours...I just feel my coffee is very samey in flavour ....maybe time to shift my mazzer mini too :

I mix it up a bit & experiment all the time

There is no one way
Sometimes I drop into a cold roaster
Sometimes I drop into a hot roaster

For bigger than 800gr roasts and mixed lots of Single Origins I drop into a cold roaster and stabilise

Then you can blend separate roasts
I sometimes roast one batch darker and one lighter, then blend

Surprising what you can achieve

KK

[scollops]

Re: KKTO Few months on

Cheers both - cant think of any simple options I can play with. KK do you still follow the same process on yours...I just feel my coffee is very samey in flavour ....maybe time to shift my mazzer mini too :

[Koffee_Kosmo]

Re: KKTO Few months on

Need better roasting thoughts ideally - I did put my thermoprobe on to see the temps - which does show the heating up and down and hard to maintain...

And

i dont have a KKTO but i do have all the parts...

the thermostat issue and cycling power is a hard one to beat, you would need to modify the TO using something like a triac based controller or maybe phase angle control to keep the heat "on" but also variable for control.

but it takes the simplicity out of the design.... as you need to have it done by a pro for safety. The fan and heating would need to be on separate controls etc.

to get full control over heat and fan it might even be better to scratch build a TO or another sort of roaster? thats going to take more than $100 (cost of a TO?) but and will end results be better?

CS Member Borat 123 has had a pro modify his TO oven to take the ON/OFF thermostat out of the equation

He will be along soon to shed some more updated info on this over and above what he has already posted on another thread
http://coffeesnobs.com.au/YaBB.pl?num=1292925707

KK

[maheel]

Re: KKTO Few months on

i dont have a KKTO but i do have all the parts...

the thermostat issue and cycling power is a hard one to beat, you would need to modify the TO using something like a triac based controller or maybe phase angle control to keep the heat "on" but also variable for control.

but it takes the simplicity out of the design.... as you need to have it done by a pro for safety. The fan and heating would need to be on separate controls etc.

to get full control over heat and fan it might even be better to scratch build a TO or another sort of roaster? thats going to take more than $100 (cost of a TO?) but and will end results be better?

[scollops]

Been using my KKTO for a while now with good results overall.  I have followed the roasting profiles from KK - using the thaw for 5 mins etc.  My questions are, the temps from the dialled in setting seem distant to actual - so hard to keep a consistent temp as the light goes out and temp drops.  I have insulated as much as possible though. 

in my pursuit I am finding my coffee tastes pretty much the same - great for consistency not when then they are different beans...  Sure there is some changes but thats my taste buds.

I tend to pull on the break of second crack - I used to do 20 seconds in, but wanted to see if I could pull some of the SO flavours from blends.

Anyone else got a KKTO with any thoughts or things that I could try ?

i use a towel around the outside to insulate, silver foil also inside the inner wall with some degree of success.

Need better roasting thoughts ideally - I did put my thermoprobe on to see the temps - which does show the heating up and down and hard to maintain...