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I - Roast
Ascholten
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Posted on 06/01/2006 7:21 PM
The airflow in the I roast can significantly alter the roasting profile of your batch of coffee. The more air movement, the cooler the beans will be in the heating chamber, as the heat gets carried away faster. With this, the slower the movement the hotter the roast temp is. Normally this is not a problem as the engineers pretty much designed this into the workings of the I roast.

Now when we are talking about decafienated beans, it's a different world. Decaf's typically have very little chaff in them, so tend to not follow the 'typical' roast pattern of a normal coffee. One will find themselves having problems getting the beans to first crack, or not stalling somewhere along the line. Now throw in the fact that decaf's tend to start out darker to begin with, and the initial smells of the beans may be different, and you can have a real issue trying to figure out what's really going on with them.

One trick that I have found that works VERY well is to first roast up a batch of normal coffee in the I roast but do NOT clean out the chaff collector.

(The I roast has a metal chaff collection cup/screen that is supposed to be cleaned out after each roasting).

Leave the chaff in and then do your Decaf as you would a normal coffee, paying attention to the color and smells and specifically listening for the crack and you should find that it will roast pretty much like any other normal coffee will roast this way.

What happens is, the chaff being left in there, slows down the air flow enough that the heat in the lower chamber is kept up where it is supposed to be, just like with a normal coffee, when it gives up it's chaff at this stage.

This sounds like a big pain but honestly it's a piece of cake, and the decaf's are terriffic coffees. Gone are the days of the bland crap you may be used to getting at the stores. I have roasted decafs and set them right next to normal coffees and asked people to tell which was which and they could not. With a little attention you will make a decaf that is just as full flavored and full bodied as a regular coffee is. Trust me, your decaf drinking friends will go crazy over this stuff.

Aaron
Bean there Done that, donated the T-shirt to the Church of the Second crack.... St Beanyface
 
Mike
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Posted on 06/01/2006 8:24 PM
Aaron,

Good trick. This will, hopefully, become a repository for other folks to deposit little tricks such as yours. This could become a real resource for the newbie and experienced roaster, alike

Mike
B)
 
Ascholten
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Posted on 06/02/2006 9:03 AM
As mentioned before, airflow has a large impact on temperature, and in this instance, bean movement. Bean movement is critical in ANY roaster for getting an even and good roast. The airflow in the I roast is what moves the beans around in the machine, in and out of the bottom heating chamber and overall keeps the thing running nicely.

Now as beans roast, they expand. Some beans don't expand a heck of a lot, while others expande HUGE amounts of their original volume. I had a peaberry I did the other day that expanded like I never seen before. If you know the characteristic of your beans, you can compensate for this by putting slightly less into the I roast to roast it. That allows for the extra expansion so you are not 'clogging' or 'choking' it off with an excessive amount of beans in the airflow chamber.

Sooner or later though you will find yourself in a situation where you have more beans in there than you really should and it's starting to give you movement problems. The I roast can compensate for this a bit by giving a 'burst' of higher speed air movement as it senses temps rising, but it can only do so much. Sooner or later you are going to end up with the I roast trying to cough beans out of the top of an expanding mountain of beans and not doing a very good job of it.

This can result in anything from an uneven roast to burnt beans if they start stalling completely.

There are two tricks to get you through this situation with minimal problems. #1 pick the i roast up and tip it at about a 45 degree angle away from your body. Tip the top of it, so that the beans are sliding away from the center 'chute' in the i roast and towards the outside window. Now start rotating it about 1 Rev every second or two, so as the beans come up to the top, they slide out to the window and it's getting a gentle even 'swirl'. This will keep them moving through the heat chamber and finish the roast with no ill results. I have done this on several occasions and it works fine. You may also find yourself in this situation often if you are one who likes to push it to the full 6 ounce capacity.

If your problem is really severe then you will want to turn the cap (NOT the chaff cap or you will end up with a brown snow storm to clean up), about a 1/4 inch just to it unlatches and let it 'float' on the cushion of air that will come out the sides of it. By this time you will probably have collected a significant amount of chaff in the collector, which is impeding the airflow a bit, (as it normally does) this will kind of bypasses the chaff collector and the restriction to allow more airflow to push the beans around. I have used this method a few times and it will save your butt from burning a batch of beans, though i do not recommend using it often or as a normal mode of operation.

If you find that you now have too much airflow, you can push the cap back down a bit with your hand (use an oven mitt or other thermal insulator as it will be VERY HOT) and regulate the flow if you must, but I have never found this to be a problem at this point, because you are already generally overheating the beans to begin with .

Using either of these 'tricks' will pretty much guarantee you a decent roast out of your I roast no matter how hard you tried to screw it up Grin

Aaron
Edited by Ascholten on 06/02/2006 9:05 AM
Bean there Done that, donated the T-shirt to the Church of the Second crack.... St Beanyface
 
Bandman
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Posted on 12/06/2006 9:32 AM
I just bought an i-Roast and was wondering if anyone here has experience with attaching a vent tube.

I live in a twonhouse and the range hood doesn't vent to the outside. My fist roast was a success but my entire place smells of the roasting smoke. I understand that roasting in the garage or outside will not work with ambient temps below 60 deg (winter here is much colder than that) so I am looking at options for a more "odor free" roast.

Input / ideas?

Scott
Edited by Bandman on 12/06/2006 9:32 AM
 
Ascholten
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Posted on 12/09/2006 1:06 PM
just make sure you use the aluminum hose and not the plastic type dryer hose to vent it or you might melt it / start a fire.
Bean there Done that, donated the T-shirt to the Church of the Second crack.... St Beanyface
 
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