IRoast Roasting Profiles??

[theosmum]

Re: IRoast Roasting Profiles??

I owned an Iroast 2 for 18 months before I read the below thread and followed Hazbeans advice to swap the installed 1000 ohm resistor for an 1800 ohm or 1k8 resistor.
I havnt looked back!!!! please.....take at look at this thread and just go do it!!!


http://coffeesnobs.com.au/YaBB.pl?num=1176777753

jo

[recurve_boy]

Re: IRoast Roasting Profiles??

I got an iRoast 2 a couple weeks ago (this is pretty much the best option for an apartment dweller). So far so good on Preset 1 & just changing the roast time.

I wish it was quieter so I dont have to roast on the balcony.

http://www.flickr.com/photos/10360653@N06/3780248160/in/set-72157621793816793/

Coffeesnobs needs some better search methods. I had to use google to find this thread ...

[TimA]

Re: IRoast Roasting Profiles??

The I roasts do seem to have a reputation for getting hot quickly and burning beans.

Its worthwhile to checkout the mods for this machine on the Sweet Marias website. I found the mods substantially improved the burning situation.

The other thing you can try if youre in a cold area is to store youre beans outside. It was about -2 in Canberra last night so the beans stored in my shed were quite cold. I roasted some Sumatran beans on the preset 2 cycle which appeared to come out well.

[FGOB]

Re: IRoast Roasting Profiles??

I have a new IRoast and the first roast I did on Preset 2 with a cup of Columbian Supremo Carmelo were burnt and had to go straight into the bin.

I repeated the experiment carefully watching the beans and I waited until they had a nice dark browm colour and and just starting to oil up and hit the cool-down buton three minutes before the end of the program.

The result was excellent. I do like my coffee on the well roasted side with just a slight bitter edge.

[TimA]

Re: IRoast Roasting Profiles??

The annoying thing is that at the better part of $400 a pop your shouldnt need a thermocouple!

[imschris]

Re: IRoast Roasting Profiles??

Thank you Mal, Ill give it a try.

Chris

[Dimal]

Re: IRoast Roasting Profiles??

Hi imschris,

From what Ive been able to find out about the type of control these units use, it would seem that they are at best a simple Proportional Controller and more likely, an Open Loop Controller. What this basically means is that no matter what you do with regard to programming, you are always going to see an error between the temperature you set and the actual temperature inside the roasting chamber.... from what you have described of your own experience with your particular roaster, it is more likely that the latter of the two options of control is the method used.

I guess the only way you are going to "know" what the actual temperature is inside the roasting chamber, is to thread a thermocouple into the chamber somehow and attach this to an appropriate Digital Multimeter..... Jaycar and Dick Smith have suitable DMMs that come with their own t/couple and connector for less than $30.00. At least you would be able to plot a temperature profile for your I-Roast that correlates to the actuals you are trying to achieve. Im pretty sure that lots of owners in the USA have done this with their I-Roasts and there-after end up with a much more satisfying end result. Might be worth a go.....

Cheers,
Mal.

[imschris]

Re: IRoast Roasting Profiles??

Guys, I have been perplexed with my IRoast machine, since I bought it last November.
It would burn cofee to a crisp in a matter of 5 minutes. Aftrer reading about the chaff filter correction(and my machine was faulty in that respect), and performing the simple modification, things did improve somewhat.
Never the less, either my temperature readout is out of whack, or I dont know how others can roast for 10 or 12 minutes.
The best that I can do is 6 minutes, with settings of
Stage 1 162C for 2 minutes,
Stage 2 180C for 2 mins and
Stage 3 200C for 2 mins.
Using either Costa Rica or Guatemalla beans, and at an ambient temp of 27C. Quantity is about 1.6 scoops, with the scoop provided. The recommended maximum is 2 scoops, but I find that with this quantity, some of the beans dont reach the right colour.
The readouts are as followes: 1st minute 178C, second min 192C, 3rd min 201C, 4th min 209C, 5th min 213C, 6th min 218C.
(Shouldnt these temperatures be lower than set? Toms test at Sweet Marias suggest that they should be 20-30 degrees lower than those set!!!)
This gives me a darkish but not oily roast, which tastes as good as that purchased and roasted by the same coffee supplier.
This though makes nonsense of the pre programmed settings and what others are experiencing.
Perhaps the supplier of the equipment, if he monitors this, can provide an answer?
As it stands, I now go simply by colour. I use a sample of roasted beans of the same type from my supplier, and stop the roasting when it reaches that colour, and 6 minutes is it.

[TimA]

Re: IRoast Roasting Profiles??

Has anyone roasted the Nicaraguan Altiplano in the I roast. The I roast seems to roast all my other beans beautifully evenly but the Nicarguan roasts fairly unevenly.

[AndyCJ]

Re: IRoast Roasting Profiles??

Man... Ive got to get to St Ali, thats 3 times Ive heard the name mentioned in the last 30 minutes....

...maybe a trip at lunch on a rainy day (like today!)

[luca]

Re: IRoast Roasting Profiles??

Im now in the possition where I have a little too much roasted coffee from my experimenting. Oh well things could be alot worse!

Thanks for the help. Tim

Wow. Who new I could be helpful; Ive only been roasting for like two weeks!

Im with you on the roasted coffee thing. The family hit me up hard last week, so I was using like 1-2 day old beans and running out. Thank god that I picked up some Sulawesi Kolossi, roasted, from Mark D at St. Ali yesterday. I gave half the bag to an unexpected friend from Sydney, so Im imposing a moratorium on coffee tomorrow till my next stuff is ready.

Timor Maubese 24/10/05

180C/3:00
210C/4:00
235C/6:00

140g/116g

... but all of that is from memory.

Dont know how to describe the roast colour, either, other than really, really even. I guess that itd be a 1 or a 2 on the graphic that I posted earlier, but thats not saying much - its not a great scale! The first roast after you clean these things seems to be like that ...

... anyhoo,

Cheers,

Luca

[TimA]

Re: IRoast Roasting Profiles??



b) I just took a flick through Sweet Marias.  Apparently a faulty chaff collector could be responsible for overly fast roast times.  There are instructions on how to fix it here: http://www.sweetmarias.com/hearthware.iRoasttipsheet.html

(See "Quick Alteration to Chaff Collector for iRoasts that are running too dark")



Luca, I think you hit the nail on the head with this one. I made the mod outlined on sweetmarias. It took 5 mins and the machine is working a treat!. The onboard roasting temps were markedly lowered. The roasting times have been extended by at least several minutes and theres heaps of time to hit the cooldown cycle if needed.

Im now in the possition where I have a little too much roasted coffee from my experimenting. Oh well things could be alot worse!

Thanks for the help. Tim

[luca]

Re: IRoast Roasting Profiles??

Correct, nunu,

In terms of amount of beans, the volume is usually more or less identical, but I measure by weight. The Malabar is way out of whack because it is monsooned, but the volume was probably slightly more than usual. I have found the bean agitation to be better using 10g less than recommended. I dont have a multimeter, so I cant really say much about temperature, just what Ive set into my machine.

Ill probably move to Toms brazillian espresso profile, though, as its a softer start. (The mountain top that we played around with today was all over the place). Toms profile is something like:

176C/3:00
210C/4:00
230C/4:00

... but thats just from memory. You can see that it has a slower ramp-up. I guess that this would mirror the roast profile of a drum roaster a bit more, in that it is preheated and has a massive drop in temp when the beans are added, then slowly ramps up.

Ive got a quick snap of Marks rig to post up, too ...

Cheers,

Luca

[nunu]

Re: IRoast Roasting Profiles??

Looks like starting and finishing weights of the beans. 20g loss per batch is pretty typical.

[TimA]

Re: IRoast Roasting Profiles??

These look great Luca. But can you tell me why you have two different weights at the end of each profile. Do you find your machine roasts hotter or cooler with a smaller amount of beans. Tim