iRoast Roast 1
(Vienna - 11min) May 31 2005
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Roast 1 Information
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Type: OCE House Espresso Weight: 150 grams 0-load Volts: 126.9V Load Volts: 117.9V Ambient: 81dF Humidity: 55% |
Total RoastTime: 11 minutes ROAST PROFILE Stage 1: 325dF, 5min. Stage 2: 390dF, 7 min. Stage 3: 460dF, 3 min. |
Was trying to achieve a 12+ minute roast cycle to Full City+(+), at the darkest, about 455-465dF final bean temperature
This the last last of my OCE blend - Monkey Blend is entirely different, the individual beans being larger and heavier, and producing more than 200% greater amount of chaff.
This roast was too accelerated in the early phase; the drying ramp-up 80F-300F should be extended, the heating phase 300F-390F is okay, but the beans were not evenly heated (not an even color, at 380F). If I had ended this roast 4min. after first crack started, it would have been more drinkable. Took it to 480dF to observe the ramp at the end of the roast.
In the above roast I reached a approximate Vienna roast, a bean temp. guessed at 465dF - at a final bean bed temperature of 480dF, so it's possible that the bean bed thermocouple readings are between 10-15dF high, towards the end of the roast, compared to actual bean temp.
My problems with this roast begin around 8 minutes. The temperature shoots up 22dF between minutes 8 & 9, and 30dF between minutes 9 & 10. I'd like to maintain a more moderate rise. The third iRoast stage never happened. After 8 minutes, the iRoast temp readout becomes almost useless. Actually it's almost useless in general, in that it's inconsistent--if roast attributes are varied.
My roasting plan is to next work with some SM Monkey Blend, roasting the same profile at 120 grams, to see how greater airflow and less chaff buildup affect the end stage of the roast -- first a bit of voltage experimentation (see Roast 2 for that), and see Roast 3 for a 120gram roast at the same voltage setting as Roast 1.
Options to extend the roast further:
Voltage can be lowered,
At about 8.5 minutes can open/close the top screen.
Can extend Stage Two up to 8 minutes at 390dF (medium fan speed) or 380dF (high fan speed).
(Settings up to 385dF produce high fan, so, for instance a profile of:
Stage 1: 325, 4min / Stage 2: 390 7 min.
is the same as:
Stage 1: 390, 11 min.
Cupping I have cupped from Roast 1; at 48 hours it was moderately drinkable. Its best flavors are deep chocolate, and when I get the pour just right, a bit of woody resin, touch of must, hint of wheat, almost grassy, but not quite. In general though the blend lacks complexity and detail, mouthfeel is pretty good, but body a bit thin. Aftertaste has a rough edge to it, lingers nicely.
At one week in a mason jar, a different experience! Fuller body, less bitter, great mouthfeel, dark chocolate, intense. Not much aroma. Crema was rich on the pour, but didn't last long -- this may be due to my extraction being a little off.
Gear A note about gear and prep -- I've been living with a Miss Silvia PID and Macap M4 grinder for three months. I have a background in espresso preparation, and did large-scale roasting, waaay back when (specifics of roasting not recalled]. I've tested my Silvia water temp. with a thermocouple, and, we have good water where I live (tested also); an NSA type large carbon/mesh filter/UV removes chlorine and bacteria. I think the Silvia, though pretty easy to use (I like the rituals, the PID is great), is kind of borderline. Commercial equipment is a dream, by comparison (temp stability, pump strength, etc.). But what would reasonably replace Miss Silvia PID, at less than twice the price (around $650.)? The Macap likewise has its quirks, mostly that it's a stepped grinder. The steps are small, but not quite small enough (half-steps in the espresso range would be a major improvement). With each new roast there's a tuning-in process, getting the right step, basket fill level and tamp pressure (mostly, tamp pressure variation, normal or slight overfilling, at the right step will do it). I go by speed of pour, resulting volume, and color coming out of the portafilter.
I may not be as assiduous as some -- for instance I'll probably not go to a crotchless PF, and I'm not looking for the 'perfect shot.' I would be happy getting consistent high quality, with varying roasts and blends--creativity, variation, freshness, and the do-it-yourself aspects draw me to home roasting, oh, did I mention cost.
Richard G
comments welcome. email
gilbert(at)iyume(dot)com
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