HomeRoast Digest


Topic: Newbie introduction and some (likely rare) questions (4 msgs / 152 lines)
1) From: Garry Turkington
Hi all,
I started roasting earlier in the year and after finally getting over the 
astonishment that even my uhm accidental roast outcomes were vastly better 
than any store-bought beans am finally ready to start honing my skills.
I bought an IR2 from SM and after they dealt well with the first unit 
being faulty have bought all my beans from there also.  So that's all 
good.
As mentioned I've liked almost all my roasts but have been finding the 
results surprisingly erratic.  First thing is that most sample curves
  I see online for the IR2 would see me produce nothing but charcoal.  A 12 
minute curve that claims to hit FC at 10 minutes for example will likely 
see me hitting 2nd crack maybe as early as 7-8 minutes.  I've read that 
some IR2s roast hotter than others (I assume inconsistent temperature 
sensors) so I've been running with the assumption that mine is lying when 
it tells me I'm moving well through 2nd crack with a temperature at 400F 
or less.  Which is fine, assuming a 40F variance has actually started to 
give me more predictability.
I've been very careful with batch sizes and recently roasted to FC+ some 
beans that took 7.5 minutes to get there, roasting on my deck in 80F 
weather which I accept is likely sub-optimal.  I repeated the roast at 50F 
early the next morning and it took around 11.5 minutes to get to the same 
roast.  I know that ambient temperature and voltage fluctuations can 
alter a roast but with this sort of variation I'm finding it really hard 
to hit my intended roast.  Even a modest 10F ambient temperature (or maybe 
voltage, I need gget a meter) difference seems to alter the roast 
noticeably.  So my  question becomes how on earth to get consistent 
results with such seeming variance being caused by outside factors?  It's 
hard to mitigate a 40% variation in required roasting time!
I've tried numerous custom roast profiles but am finding it difficult to 
get ones which reliably see space between 1st and 2nd crack.  But given 
the variation I see on the same curve above I can't tell if I need tweak 
the curves or am primarily having the environmentals making my roasting 
life more challenging.
Which brings me to my last point.  I happen to be blind which means I 
can't rely on visual cues to monitor roast progress, I'm relying on sound, 
time and (to a lesser degree) smell.  Though I used to believe I preferred 
darker roasts I've been getting the greatest coffee from roasts in the C+ 
to FC range, which I find really hard to hit especially when an 
environmentally compressed roast sees 1st and 2nd crack fall on top of 
each other.
So if anyone has any heuristics they could suggest to help me stablize my 
roasts and get more consistent ways of hitting my desired roast level 
they'd be much appreciated.
Regards,
Garry
-- 
Garry Turkington
garry.turkington

2) From: Jerry Procopio
Garry,
Welcome!  Enjoy the journey.
JavaJerry
Garry Turkington wrote:
<Snip>

3) From: Robert Gulley
Garry
Welcome to home roasting!
I have not been roasting long, so take this for what it's worth. I 
also have the IR2 and have been getting pretty consistent results (of 
course I am able to monitor the roast visually, and so I am less 
dependent on sound and smell as you will be). However, what I have 
found is that indoors the ambient temperature of the house stays 
fairly consistent (that means hot around here this time of year) so I 
keep a fan running across the room to drop the temp a bit, and to 
dissipate any smoke. I have not found the smoke to be objectionable 
at City to Full city+, and so roasting indoors is not a problem for 
me - you may be different. I think you will find more consistency if 
you are able to roast indoors.
As a base line, what I have found is that the suggested starting 
point that came with Tom's tip sheet has worked well over-all -- all 
of my roasts are at worst decent, and at best, pretty much right 
where I want them.
I find that when I take Tom's numbers almost all of my roasts end 
about 2 minutes early from the 9minute 30 second profile. I can 
easily hear first crack, and some beans start to move into second 
crack around 2 minutes later, and so I am usually stopping it just 
before second crack.
I think you limitation in not being able to watch the roast will 
cause you to rely on the smell (and sound to a lessor extent) and so 
I would recommend working with several pounds of the same coffee 
until you get the roast you are wanting based on time and smell. If 
you vary coffees too much I think it will be confusing. This will 
limit your initial enjoyment of getting to sample all different types 
of coffee, but in the long run once you have "mastered" a given roast 
from a given region, it will give you a baseline by which you can 
judge other coffees from the same region.
As for the temperature readings on the IR2, keep in mind it is 
measuring the air in the chamber, not the actual bean temp. Often 
when people are talking about temperature they are measuring temps at 
the bean itself.
Hope this helps a bit - and hang in there - the results are worth the effort!
Robert Gulley
At 11:52 PM 10/4/2007, you wrote:
<Snip>

4) From: Mike Koenig
Hi Garry,
Welcome to the Zassenhaus fan club list (sometimes known as the Sweet
Maria's homeroasting list)  (once you are here for a while, you'll get
the joke)
Try using less beans in your IR2 to slow it down a little.  Even 10
grams less can make a difference.  Less beans means more airflow,
which results in a slower roast.  I was using 150-160 g in my IR1
(depending on my desired degree of roast).  Unfortunately, the
i-Roasts are notorious for unit-to-unit variability, so it will take
some trial and error to find your own sweet spot.
Another thing to try is an outlet in your house that is farthest away
from your breaker box.  I experienced a drastic difference between my
front porch (first outlet from the breaker box) and back porch
(farthest outlet).
Lastly,  using the i-Roast's actual temperature display, you can get
an idea of where the cracks occur, and adjust your setpoints
accordingly.  The temperature probe calibration also varies widely on
these units, so someone else's settings may not work for you.
Enjoy!
--mike
On 10/4/07, Garry Turkington  wrote:
<Snip>


HomeRoast Digest