Peru FTO La Convención

Beans: Peru FTO La Convención
Varietals: Bourbon, Caturra, Typica
Elevation: 1750-2200 masl
Process: Washed
Retailer: Sweet Maria's
Pre-Roast Weight: 234 grams
Roast Attempt: 17th
Roast Date/Time: March 13, 2021, 1600 CST

Per the instructions on the Behmor, I did the first handful of roasts with 1/4 pound batches and using preset temperature profiles.  Then I pretty quickly learned that that wasn't going to be the best way to use the roaster and had to figure out the manual settings, which aren't really that complicated - and you have to stand there the whole time anyway, so why wouldn't you want to take more control?  I did some research online and most people suggest using the one-pound setting - this is simply to give you more time to play with, so you don't have to worry about adding any.  So the timer starts at 18:00 and counts down; right after you start the roaster, you hit the "P5" button to enter manual mode at the highest heat setting, 100% power to the heating element.

Chamber Temperature

16:00 - 145
14:00 - 228
12:00 - 282
11:00 - 302
10:00 - 293

In my - as you can see from the number of roast attempts, still pretty limited but enough to see some patterns - experience, the yellowing of the roast tends to happen right about 10:30, or 7:30 into the roast.  This is also around the time when the exhaust vent in the roaster opens and the other thermistor becomes useful.  Before yellowing, you want to look at the chamber wall thermistor (the B button on the front of the roaster); after yellowing, you want to look at the exhaust thermistor (the A button on the front of the roaster).

The other thing I tend to do during the roast based on recommendations for how to run the Behmor is increase the drum speed when the roast hits the yellowing phase, and lower the intensity of the heating element.  Pressing D on the front of the roaster speeds up the drum; this increases airflow over the beans and helps them get roasted faster.  By lowering the heating element and increasing the airflow you're also roasting the beans more holistically; if all you do is point the heating element at them the whole time, there is some risk of the beans getting scorched (i.e. the outside of the bean roasts but the inside doesn't really get there).  I've had pretty good success with this strategy so far.

So for this batch I did indeed up the drum speed at 10:30 on the clock and lower the heat to P4 (which is 75% power).

Exhaust Temperature

10:00 - 203
9:00 - 291
8:00 - 330
7:00 - 352
6:00 - 365
5:00 - 377
4:00 - 383

My understanding is that the exhaust temperature is an okay proxy for bean temperature - it keeps going up, which the chamber temperature does not.  According to Sweet Maria's website, the internal bean temperature is about 356 degrees F at the start of first crack.  In this roast, based on sound, first crack started at 12:15 into the roast (5:45 on the time display), so the exhaust temperature reading was about 370.  Not too far off, anyway.

I try to plot out what I plan to do for a roast in advance.  For this one, since it's a high-grown bean and one that I was not expecting to be super delicate either generally or flavor-wise, my plan was to end the roast about 30 seconds past the first crack taper, going for a slightly richer medium or "City+" as some would call it.  (I personally find the "City" terminology somewhat confusing and unhelpful, but Sweet Maria's uses that in their roast guide so I need to at least be aware of it.)

First crack can be a finicky thing and varies widely depending on the coffee.  In this case, first crack was certainly audible but it was also pretty gradual.  At the start of first crack, I dropped the drum speed back to the slower setting.  It usually lasts 60-90 seconds, depending on what exactly you consider the start; there are usually a few isolated popping sounds before it starts in earnest, although I've also had roasts where I never really heard more than the more sporadic pops across the whole of first crack.  So you certainly can't rely just on sound.  In this case I kept my ears open but also kept an eye on the exhaust thermistor.  I've learned that I don't want to see it going too far into the 380s if what I want is no darker than a medium - I've roasted medium-darks with a peak of 388 (although I did once get a very good medium Ethiopian at that temperature) and a peak of 395 once produced an essentially undrinkable French+ roast.  That's a pretty small window!  Not even 15 degrees on the exhaust thermistor is the difference between a good medium roast and basically charcoal.

In this case, as seen above, the peak was 383, at least as far as I was writing it down.  Twenty seconds after the last temperature measurement, I sent the roaster into its cooling cycle.  This was at 3:40 on the display, so just over two minutes after the first pops of first crack were audible.  There were some stragglers still popping less than 30 seconds before I ended the roast, but I couldn't wait forever.  The smell had started to get a bit more to the burnt side - I'm pretty sure this is primarily a chaff thing, but it is nonetheless a signifier of how deep the roast is going.

The other thing that I did, recommended for the Behmor, was open the door 90 seconds into the cooling cycle.  The Behmor cooling cycle lasts 13 minutes and is pretty gradual - so if you leave the door closed the whole time, the beans are remaining in a fairly hot environment for quite some time and you run the risk of them getting baked.  There is of course a downside to opening the door, which is that chaff blows out of the roaster and all over the floor and counter, but it's not a huge amount and I simply bring the vacuum over and take care of it as soon as the machine finishes.

Complete Roast Time: 14:20
Post-Roast Weight: 202 grams
Loss Percentage: 13.7%

The beans looked a little darker than some recent medium roasts, but I've learned that 12-14% is the percentage that I'm looking for to get a medium.  12% is maybe on the medium-light side.  13-14% is definitely a full medium, I would say.  Once you get to 15% you're starting to talk medium-dark - every roast I've done that reached that level of loss has been medium-dark or higher (my one way overdone Sumatran hit 20%, which was pretty extreme).

Peru FTO La Convención

These were the beans this morning, one week off roast.  As noted, the external coloring was a little darker in places; it also wasn't entirely consistent across the batch.  At the very least, I've seen more consistent batches - if you really zoom in close, I can actually spot what appears to be a drop of oil on the outside of one of the beans, meaning that individual bean actually got up around second crack (when the internal cellular matrix of the bean starts to break down, releasing oils which then make their way to the outside surface - this is why dark roasts get oily).

However, the beans brewed like a medium, so I'm inclined to say you can't just judge a book by its cover here.  I ground the beans to a medium-coarse, which is the setting I use to brew in the V60 pourover - on my Capresso burr grinder, it's between 5 and 6 (out of 16 grind size settings going all the way to extra fine).  Total extraction time was about three minutes, including the 30 second bloom.

TASTING NOTES: Like other Peruvian coffees I've had before, the body on this one is remarkably creamy.  The acid at the front end is somewhat mild and sweet - I would compare it to green apple.  Behind that are some really classic coffee flavors - notes of dark chocolate, toasted almond, and a hint of cinnamon.

VERDICT: The Peru FTO La Convención came out a solid medium roast, with roaster temperature and weight loss across the roast being perhaps slightly more predictive than color, which was not the smooth even brown that some roasts have produced.  Flavor was definitely what I would have expected from a medium, with a nice balance between an acid pop that quickly mellows and a creamy mouthfeel to the body, followed by a foregrounding of classic medium notes like chocolate, spice, and toasted nut.  If I'd gotten this shipped to me from a professional roaster I'd be thoroughly pleased, so the fact that I roasted it myself is pretty exciting!