I-Roast 2 program question

[b]

Re: I-Roast 2 program question

Ive made no mods (and at this stage dont intend to as Im an idiot with anything electronic or electrical).

By dropping the programmed temperatures compared to P2 I extended roast time out to 7:00 to 7:30 minutes. The indicated temps exceeded the programmed ones by quite a bit, but consistently across every roast if you see what I mean. 168C = 178C; 180C = 209C; 210C = 225C. No idea what the actual temps are.

By dropping it further I extended some recent batches out to 8:30 (162C program = 174C indicated, I think for 6 minutes plus a couple of hotter minutes). However the outcomes were not as good. Severe mousetailing (my grinder struggles with oily beans, though these did not look externally oily), with less complex though still perfectly acceptable aroma and flavour, with the same roast darkness (ish). (I need to pick up a CS card with my next order to more accurately compare the results.)

All this with one batch of Ethiopian Limmu.

Ive since just done some Sumatran beans, which expand a whole lot more and circulate a whole lot slower - too slowly. I had to reduce the amount going in by about 25%, which brought the roast time down by about 45 seconds. Though I havent done enough to know whether there is an easy formula for quantity vs time.

I also cant discern second cracks amidst the roar.

Ill write up my scrawled notes sometime soon.

[BazzaB]

Re: I-Roast 2 program question

Hi all,
Like others I retired my popper to upgrade into one of there and to date have had little success in extending the roast time.  Mind you have only dome a few roasts to date.

For the learned one out there in i-roast land, apart from the obvious physical challenge, would it make sense to reposition the onboard TC into the bean mass to control the temp or would this just introduce another problem like too long a lag time to control the temp effectively?

Just a thought - OK maybe not the best one I know!!!

Look forward to hearing your views.

Cheers
Bazza

[hazbean]

Re: I-Roast 2 program question

Emailing iroast / Hearthware has about the same result as emailing
a brick wall. However they do answer the phone at their customer
support number; I did it when I was in Monterey at a conference.
Might be worth a try.

Yes it is frustrating that a potentially good design hasnt been
given a little more design and development effort to get past
this unsupported half-baked calibration resistor idea (which is
actually inherited from their earlier roasters but seemed to
work better there). Not to mention a little more construction
reliability. HW is being a little cynical at this point I think.

[Dimal]

Re: I-Roast 2 program question

Its the way of the world. Make em fast and make em cheap and do it with as few of people as possible and cut out customer service. When it breaks throw it away.

Yep, its a terrible indictment on the way our society has developed over the past few decades.... No wonder there is incredible pressure being placed on all of our natural resources. Anyway mate, Im pretty sure youre going to get your I-Roast sorted out to your satisfaction. All the best mate...

Mal.

[justintime]

Re: I-Roast 2 program question

So true. I probably will not pursue Iroast as they probably would send me another one just like it. There all made in China. It looks to me like the just build them and put in a 1k resistor and nobody bothers to calibrate them at all. Which they clearly are made to be calibrated other wise why the plug in resistor accessible from the bottom? Its the way of the world. Make em fast and make em cheap and do it with as few of people as possible and cut out customer service. When it breaks throw it away.

[sdg]

Re: I-Roast 2 program question

I tried the trick someone posted about putting your ear in the out flow with out burning it off and I did hear 1st crack at approx 6 min but never heard 2nd crack. I rarely did with the popper either, my 63 year old ears aint what they used to be.

Its not just your ears -- they dont call it the iRoar for nothing.

BTW I emailed Iroast Friday night and still have not gotten an answer.

Not encouraging. But sounds like youre making pretty good progress anyway

[justintime]

Re: I-Roast 2 program question

My line voltage is 123V . I probably could go a little lower to get the 10min roast a little darker.  Next time I will try profile 2 which is supposed to be darker.

Since I use resistors in my work at home I have a book with approx 1000 resistors of different values all 1%.  I also have some little screwdriver adjust pots I could solder on permanently in place of the resistor, but what Im looking for is a longer roast time and repeatable, besides if this one blows up another one would be totally different.

Last night I did a roast using 2min @ 220F, 3min @ 390F, 4min @ 450F. The roast came out a tad lighter than the last. You are right about the low end. I observed the low end readings were running about 10 to 30 degrees hotter than programmed and got closer on the high end. It also did not oscillate as much as the last one. 1 more minuet on the low and 1 on the high end should bring it in. That would be 11min.

I tried the trick someone posted about putting your ear in the out flow with out burning it off and I did hear 1st crack at approx 6 min but never heard 2nd crack. I rarely did with the popper either, my 63 year old ears aint what they used to be. I got about 6" above the output and to the side of the flow.

The last roast cupped is very mild compared to what I was getting with the 6 min roasts. Im doing 60gr batches.
I had never taken a roast to charcoal before I just wanted to see it. My garbage disposal loved them. I now have about 3 batches to drink and have thrown away about 3, so it will be a while before I try more. Takes me about a week to drink 60gr.

 BTW I emailed Iroast Friday night and still have not gotten an answer.

[sdg]

Re: I-Roast 2 program question

The supplier I found was in Qld, unlikely to be closer than Ringwood ...

Oh, its only a *little* further north

Might be warmer 8-)

[sdg]

Re: I-Roast 2 program question

Wow -- you were pretty brave taking that 1st lot thru the whole 10 mins -- any darker and it would be "call the fire brigade"!

Not sure Id want to put them thru my machine (either the grinder or the coffee machine!) tho -- perhaps a decent burial with full honours is in order ;D

"They gave their all in the name of science" sort of thing.

The second batch looks good, maybe even a little light. Dont suppose you were able to hear any cracks, so as to have an idea what stage theyre at?

BTW, preset 1 *used* to be a "light" roast, but not anymore -- 450*F is basically the nearly flat-out roast (I think 485*F is the max you can program)

[hazbean]

Re: I-Roast 2 program question

" ... after 1 min started to oscillate from high to low. It never did this before."

That is exactly what I observed when I did the mod.

Your temp diffs are IIRC consistent with what I was getting. With a
TC installed I tried to set the resistor so that with a "staged" profile
the TC reading and programmed setting would be close at the
end of each stage. This worked for later stages, the machine has
a mind of its own for the first three or four minutes.

Im surprised at the high R values you have. Just out of curiosity,
what is your line voltage?

Love the photo -- the contrast is sublime. A cupping comparison
will be interesting. The second batch looks very nice.

I ended up with 12 to 14 minute roast times. I think 10 to 12
would be pretty good, 8 perhaps a bit fast still.

Simone wrote: "Or even better, a packet of the things, since once resistors go in, they dont come out..."

Thats true, a few is a good idea. I had three or four set up with different
resistors. I clipped the leads short and soldered resistors across them to
give plenty of flexibility. The variable resistor I soldered across long leads
so that it could just sit alongside the roaster.

The supplier I found was in Qld, unlikely to be closer than Ringwood ...

[justintime]

Re: I-Roast 2 program question

Here is the finished picts.

[justintime]

Re: I-Roast 2 program question

I started with a 2.2k. I used the Profile 1 of 450F and 10 min, which comes pre programed and is supposed to result in a light roast. After 10min it was charcoal. I checked the temp and for most of the roast it showed 455F. I also noticed it started out high fan and after 1 min started to oscillate from high to low. It never did this before.
I next changed to a 3.6k resistor. I checked the temp on the lcd and it was mostly 30 degrees F lower than the program temp but got to 455 at the end. This time it started out at high fan and imediatley switched to low then after a while it started to oscillate then at the end went to high.
Here are some pictures taken at 2 min, 4min, 6min, 8min and the finished result. What do you think?

[sdg]

Re: I-Roast 2 program question

Hi Mal,

The idea of further dissecting (or perhaps that should be, demolishing) my iRoast is quite tempting, I have to admit :

However, now (thanks to you and Hazbean) I know the correct gizmo is obtainium in Oz, I think it will save ever so much trouble if I just get the right one

Or even better, a packet of the things, since once resistors go in, they dont come out...

[Dimal]

Re: I-Roast 2 program question

I spose theres always Jaycar, DSE, Altronics and a few others. Dont know how easy it is to remove the PCB with the socket on it but if its not too difficult, then you could take that with you and try before you buy? :-?

Mal.

[sdg]

Re: I-Roast 2 program question

Thanks Mal, you found a different source. I could dig up the details of mine in a day or two when I get home if needed.

Id still be interested to know about any other suppliers, just in case theyve got an outlet closer to us. Otherwise off to Ringwood we go

justintime, take care with different connectors, check that they are a really tight fit, and that the contacts line up, I had problems with substitutes until I found the real thing.

Quite so. And they all looked so plausible... :-[