Insulated Corretto Pan - first experiences :-)

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

Ahhhh the ole but!
Very interesting… thanks Mal

[Dimal]

Re: Insulated Corretto Pan - first experiences :-)

But does this mean that 2C will always be at exactly the same temp, no matter what roaster youre using  :-?

Pretty close to it, but.... :

Only on the same roaster in the same location in identical ambient conditions, et al.....

No doubt there will some small variability due to bean density factors and what have you but it is amazingly consistent just the same,

Mal.

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

Wow!
Thanks Mal! But dont know if its possible to control growing altitude in my shed! ;D

Have to find other things to ponder!

2nd-Crack is related to the sudden fracturing of the cellulose bonds of the individual cells in the beans and nothing to do with moisture

But does this mean that 2C will always be at exactly the same temp, no matter what roaster youre using :-?

Matt

[Dimal]

Re: Insulated Corretto Pan - first experiences :-)

Hi guys....

2nd-Crack is related to the sudden fracturing of the cellulose bonds of the individual cells in the beans and nothing to do with moisture content as this will be long gone by the time the bean mass reaches 150deg.C.

Beans with a preponderance to the formation of divots or craters, seems to have more to do with the altitude at which the beans are grown than anything else Ive tried to correlate with the phenomenon, i.e. lower altitude beans seem more susceptible and benefit from a gentler profile, which by coincidence, also seems to benefit the flavour profile in the cup.... 8-)

Mal.

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

are reportedly "Generally due to too much heat from 1st crack to 2nd crack".

Thanks Graham. That makes a lot of sense…
Sounds like it might have something to do with the water coming out too fast at the beginning? Would that mean than un-modded poppers would be really susceptible to this? Also that wet processed bean (ie your PNG?) might be more prone to it than sun-dried where they have lower moisture content anyway?

Matt

[GrahamK]

Re: Insulated Corretto Pan - first experiences :-)

Not sure if this is helpful as I dont use a Corretto, but the "divots", or "craters" as they are also known as, are reportedly "Generally due to too much heat from 1st crack to 2nd crack".

http://www.home-barista.com/home-roasting/coffee-roasting-defects-pictorial-t13587.html

There are certain beans that I roast (e.g. the PNG Waghi AA), that seem more succeptible to these than others, and to minimise that I change the ramp up to 2C to be more gentle, and that seems to work.

GrahamK

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

BTW i think im confused in my terminlogy - what is te difference between tipping and divots?   

Just done a search - and I see!
So - Ive had lots of divots - but no tipping!

As to the differing temperatures between correttos, Ive just had a thought.
I use a non-adjustable Ryobi 2000w gun flat out for all my roasts, just adjusting the height. I have a tomato can chimney on my lid, plus a 3 inch extension on the gun. The main working height I use is quite high, with the end of these two units basically lining up. This means that the gun element is about 300mm off the bean mass, as opposed to an adjustable gun sitting on/into the actual lid (element height about 100mm above bean mass).
Im wondering if, despite a similar temperature rise profile, my setup gives a slower browning on the outside of the beans (and subsequently later 2C when the outside hardens/splits again) but allows the inside to heat up more, raising the overall bean mass temperature higher - hence my higher readings?
When starting I saw lots of 215-218 readings, which a use as my benchmark for a while - but in espresso was completely undrinkable in the DBC house! So I wonder how much reading error/difference is actually in the DMM/setup, and instead whether the temp of 2C can be a variable between the outside browning and inside temp?
Just thinking aloud :

Matt

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

Whats your colour scale after dumping at 222 deg DBC?

Hi Gary
Agree with the syrupy pour
I would say CS8-9 (that bottom pic this page is pretty standard). Im sure it has to do with the probe placement and bean mass etc.
In flavour (which seems a bit more reliable to compare) I found that from 219-221 there were nice aromas but slightly light-on in body and a slghtly sour taste in a doppio (all I drink really that can give me a full flavour analysis) - but hit that magic spot at 222 the sourness went away, body fullness & depth increased and aroma in the bag improved.

Current roast times are at 16-17 minutes.
Ill try a slower gentle roast tomorrow, stretch it out to about 18-19 min and then taste.

Ive tried some slightly faster roasts recently between 1C-2C (not reducing temp again at 205) which would only take about 4-5mins - but started getting divots - so slowed it back down.

BTW i think im confused in my terminlogy - what is te difference between tipping and divots? :-?

Happy roasting today! Im done till next weekend

[sidewayss]

Re: Insulated Corretto Pan - first experiences :-)

Theres certainly no turning back Mal. 

The KKTO arrives later in the week, so the coretto will have a holiday while i get adjusted to the new arrival.

Once things get sorted out, Ill compare the roasts from those two.

Thats what i do too DBC, gentle heating of the beans to stabilize moisture levels of the beans at 50 deg for 5 minutes, then start the roasting proper.
What i do though is start backing off the heat at 185 deg, which is about a minute before 1st crack so that it eases into the exothermic reaction and the profile is more controllable for the 2-3 deg per min from there til 2nd C.
I dump at 214 to 215 deg to give me maximum sweetness according to my palate.

The pour coming out of the spout looks lazier, more syrupy, both on the Miss Silvia at home, and the "brown bertha" San Marino at work.
Theres more intensity in the flavour and seems to have extra creamy mouthfeel.

Current roast times are at 16-17 minutes.
Ill try a slower gentle roast tomorrow, stretch it out to about 18-19 min and then taste.

Whats your colour scale after dumping at 222 deg DBC?

Gary at G

[Dimal]

Re: Insulated Corretto Pan - first experiences :-)

Great news Gary... [smiley=thumbsup.gif]

Just need to become familiar with the (slightly) altered thermodynamics of the system and therell be no turning back.

Good stuff mate... 8-)

Mal.

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

Great to hear Gary!
It certainly gives a smoother, more controllable temp rise (therefore better profile) and requires much less heat input, which must be gentler on the beans. Ive certainly found it sweeter and with more body in the cup too.
Ive had some tipping in the past - but mainly when Ive tried pre-heating the pan then dumping in cold beans. I have now pretty much eliminated that now by doing a gentle pre-warm (up to 30 degrees) for the first 2 mins of erratic mixing (my BM is still on a standard dough setting) then giving a consistent heat input till 150 degrees (which takes about 6mins) then ramping up slightly (by dropping my gun by 2cm) till 195 (about 4 mins later). At 195 I drop the temp input significantly (lift gun 5cm) to reduce temp climb to just above stalling point, drop again slightly at 200 (1cm), then again at 205 (by another 1cm - 205 seems to be where the rise can start to run away again) - this input then gives a nice gentle climb all the way to 2c (222 deg in my setup), all up which takes about another 4 mins. Bout 17-18 mins all up.
This last few batches has been quite amazing - and no tipping!
Look forward to hearing your cupping experiences on these new batches

Matt

[sidewayss]

Re: Insulated Corretto Pan - first experiences :-)

Thanks to DBCs fire blanket and Mals inspired fibro coretto cover, together with some minor tweaking of the coffee roasting profile, the coffee is tasting better than ever.

With those additions, I have reduced the setting on the heatgun by up to 30 degrees for the same roasting time.
ie. Prior to mods: 420 deg. 1st C to 2nd C temp: 360 deg.
After mods: 390 deg. 1st C to 2nd C temp: 330 deg.

I can only presume the decreased requirement of heat input and heat retention helps in boosting the quality of the end result. The appearance looks better, I still get some divots but hardly any tipping.

It tastes better now in the cup, and my friends and workplace agree.

Gentlemen, my thanks for you sharing your tips and advice.

Gary at G

[DesigningByCoffee]

Re: Insulated Corretto Pan - first experiences :-)

Hi mb
I dont think mine was smoke from the fire blanket - it was when I tried to use a woolen blanket though! ;D
It only happened the first batch, so I think it was old built up coffee oil burning off - havent experienced that level of smoke since, just the general bean waftings.
And the only discolouration on the fire blanket is not from burning, but slight smoke staining around the gaps - so I think itll be a good long term solution.

Matt

[mobbarley]

Re: Insulated Corretto Pan - first experiences :-)

Dont breathe too much of that smoke (I might be a bit late)!

Wrapped my Quest in a bunnings fire blanket and did a test before roasting - didnt see any smoke.

Obviously I didnt get it hot enough as it wafted white smoke when I did a roast with it (didnt smell too strong over the bean drying smell - hard to notice). Luckily I didnt stitch it up so I could just pull it off without interfering with the roast. It might have stopped smoking but I couldnt step away from the roaster and didnt want to breathe it in.

[Dimal]

Re: Insulated Corretto Pan - first experiences :-)

Hi Guys...

The Makita HG I use actually uses a closed loop control system to manage the Output Temp. When switching from Low Fan to High Fan or vice versa, the Output Temp does shift a little but is easily brought back "on profile" by readjusting the controller wheel. Its not difficult or I wouldnt be able to do it.... :P ;D

Agree with you there too Matt.... Definitely changes the thermodynamics of the system when the pan is well insulated. The recent additions that Andy has made to the Roast Monitor software makes this easy to manage though, by tracking the "Rate of Change" trace on the chart. An excellent update for we home roasters I reckon... 8-)

Mal.