Congo Kivu Kalehe Cooperative

Beans: Congo Kivu Kalehe Cooperative
Varietal: Bourbon
Elevation: 1600 masl
Process: Washed
Retailer: Sweet Maria's
Pre-Roast Weight: 232 grams
Roast Attempt: 22nd
Roast Date/Time: April 1, 2021, 1830 CDT

Trying to get through some of the roasted coffee I had on hand, I went eight days without roasting, so it was time to get back to it.  Congo is another origin that I'm pretty new to, although not totally - in my currently dormant 50 state roaster project I had a Congolese coffee roasted in Connecticut.  (It was fine.)  Like Yemen, an origin I enjoy quite a lot, it's also a country that has had a lot of struggles with conflict, especially in its primary coffee-growing regions around Lake Kivu in the east of the country.  Hopefully, then, the ability to export a commodity crop like coffee is a positive thing for the region.

As usual, the starting setting was a manual roast on P5 (100% power to the heating element) with 18:00 on the timer (one-pound setting).

Chamber Temperature

16:00 - 147
14:00 - 231
13:00 - 262
12:00 - 289
11:00 - 309
10:00 - 294

Pretty typical progress up to the yellowing phase.  One thing I did notice was that as the coffee approached yellowing, the window on the front of the roaster got pretty fogged up.  I've seen this a few times, but only once before was it this aggressive.  I had noted that the green coffee had a slightly "wetter" smell to it when I was shaking out the beans before starting the roast (I put the beans in the drum, then shake the drum over the sink to remove some of the already loose excess bits of chaff), so this didn't surprise me much, but it was interesting to note.  I ultimately called the yellowing phase time at 10:30 on the display, 7:30 into the roast, but I could probably even have called it at 10:45.  I increased the drum speed at this point and lowered the heat to P4, 75% power to the heating element.

Exhaust Temperature

10:00 - 206
9:00 - 296
8:00 - 336
7:00 - 357
6:00 - 374
5:00 - 383

This was again fairly typical and perhaps even a skosh lower than I might have expected.  The recent Burundian roast, which was probably the most comparable batch to this one on basic merits that I've done since I started this blog, ran a couple degrees hotter at all of the post-10:00 checkpoints and started first crack at 10:45.  Here, first crack started a bit later - 6:45 on the display, 11:15 into the roast, and even then it began as a few slow pops before it really got going at more like 6:30 or even 6:15.  There wasn't much glowing chaff in this batch - I saw a bit right as I went into the cooling cycle, but compared to some recent ones it was pretty relaxed, which may have been part of why the temperature stayed a little lower.  I let the roast go all the way to 5:00 on the display because the temperature was only just over 380 (so I wasn't too worried about it) and there were still a few pops here and there.  It went from 381 to 383 right at 5:00, so I sent the roast into the cooling cycle there.  My intention was to slow the drum right then, but I forgot to do it for the first 40 seconds of cooling.  As usual, I opened the door after 90 seconds to expedite the cooling process.

Complete Roast Time: 13:00
Post-Roast Weight: 198 grams
Loss Percentage: 14.6%

I was a bit stunned by the loss percentage for a couple reasons.  First of all, the beans looked for all the world like a medium-light roast.  If anything I was initially slightly worried when I poured them out of the drum that they hadn't roasted long enough, in spite of the fact that I heard them go through first crack.  But more to the point, 14.6% just sounds like a lot when I look at the history of loss percentages I've accomplished. It's closer to 15% than 14%, and everything I've taken to 15% so far has been definitively medium-dark!  But with that said, it obviously varies.  The El Salvador Pacamara was 14%, higher than the Peru... but I would call the Pacamara a medium-light roast and the Peru a medium in terms of the way they came out flavor-wise.  That the Congolese beans seemed like they might have a higher moisture content than some other beans could explain a lot of the difference - if you knocked all of four grams of weight off the initial number (assuming a slightly drier bean) and ended up at the same post-roast weight, the loss percentage would only be 13.1% and I wouldn't have blinked.  Four grams!  So if my suspicion about the moisture is right, this should still be the kind of roast I was aiming for it to be.  But let's find out.

Congo Kivu Kalehe Cooperative

These were the beans on Sunday, three days off roast.  I was quite pleased with the overall evenness of the color across the batch, and it continued to look more like a medium-light than a full medium, much less anything darker, despite the loss percentage.  I ground 28 grams of beans on the 5/6 setting on my burr grinder for a medium-coarse grind, then brewed them in the V60 at my usual 60g/1L ratio.  28 grams of ground coffee and 467 grams of water yielded just under 15 fluid ounces of brewed coffee.

TASTING NOTES: The flavor, it must be said, was a little more suggestive of the further roast level that had seemed indicated by the loss percentage.  Not in a bad way per se, but my immediate thought on the first couple of sips was definitely "roast."  This did back off as I kept drinking, and flavor characters began to emerge.  The acid profile was something of a bitter citrus, like a grapefruit; the body was on the lighter side but not overly thin.  Floral/spice accents crept out of the cup; cardamom and lemongrass were suggested.  A slightly jammy fruit character started to work its way in as well, sort of in a marmalade direction if the oranges were just a shade to the bitter side.

VERDICT: I was worried on the first couple sips that I had overroasted the beans, but the flavor ended up being fairly complex and I think in the end I got them just about right.  On the whole it wasn't my absolute favorite example of East African coffee but it was rather good.  I have a second half-pound batch to roast, so I'll probably try to go into the cooling cycle a little earlier, by 15-30 seconds, and see if that makes any difference to just brighten it up slightly and pull out some of that initial roasty hit.