Durato Bombe Roasting thread - Page 2

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
bicktrav

#11: Post by bicktrav »

I'm drinking Happy Mug's Harrar version as I type, about a week out from roasting. It's got blueberry for sure, the wild variety, tart and a touch acidic, not a super sweet "blueberry candy" vibe. Not sure why it took so long for that note to sing, but it's there. Figured I'd mention it.

User avatar
cmapes
Supporter ♡

#12: Post by cmapes » replying to bicktrav »

Funny you mention it, I pulled a shot of it yesterday, 10 days post roast and blueberry showed up. Strange because with my first roast it showed up after about 3 days and softened by day 8. Go figure. But either way I'm enjoying it. The bag has a distinct and potent blueberry scent too.

pcofftenyo

#13: Post by pcofftenyo »

When this sort of fruit note is available in a natural processed Ethio (Hambela Guji, Daye Bensa, etc) I tend to get it more often using a 185-190 charge temp and a 20-24 max ROR. Drop stuff is overlooked sometimes but I think it makes a difference.

FWIW, ignore as you see fit, etc.

Huky, 16 oz charge weight.

User avatar
drgary
Team HB

#14: Post by drgary »

I just got to roast again after the wildfire smoke cleared. Here's today's roast of the Ethiopia Sidama Durato Bombe from Captain's Coffee. Dry cupping is promising. Added: Just brewed an ibrik the day after roast. Even while it's still warm, there's strong blueberry immediately followed by blueberry syrup. The acidity is like mild, fresh blueberries and it's well balanced with sweetness. The lingering aftertaste is blueberry syrup. This is a pretty clean cup for a natural. The mouthfeel is somewhere between light syrup and oolong tea. I'm finally getting the hang of roasting these naturals.

Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

Case17

#15: Post by Case17 »

bradm wrote:Thanks for starting this thread.

I have the second batch from Captain's. Here's my first try, which was partially botched because I didn't properly tare the scale and loaded a batch that was 40g lighter than my usual 325g. The lighter curves in the background are your roast.

image

This was a non-traditional low-and-slow profile that worked very well for a 325g batch of the Shantawene. Unfortunately the cup was really average, much like you described. Perhaps the most vague hint of pineapple if you use your imagination, but otherwise tastes like.... regular old coffee.

With six more tries to get a winner, I'll be eager to hear how your next batch comes out. Maybe we need a more traditional Rao-approved profile?
Here is my profile that resembles your low&slow one somewhat:



This one was my worst so far, though actually my first roast (had it in freezer). There wasn't much to it. My wife described one brewing attempt with it has tasting like tacos (admittedly the pour over brew was probably botched a little bit). But my better pour over with it had no fruit whatsoever and little sweetness. Presumably this one was baked somewhat, and perhaps roasting too long.

I next tried some roasts where I went for lower drop temps. This one I probably baked also:



This one had perhaps hints of blueberries in the dry aroma, but it did not make it into the cup. There was sort of a cocoa sweetness and another taste I haven't been able to put my finger on. There is also a bit of grassiness which I figure is due to the lower drop temp.
***EDIT 9/23: I have been drinking this batch for a few more days. Improved somewhat. The dry aroma contains a subtle mouth-watering fruity tartness (best I can think to describe). Still, this does not make it significantly into the cup. However, the cup does have nice cookie tastes: caramel, baked goods. I dare say it is actually good... but no blueberries at all, at least to my untrained nose/mouth.***

My next roast goes for a similar drop temp (200-201C), but I sped up the roast considerably with a high charge temperature. Will post once I taste it.

User avatar
drgary
Team HB

#16: Post by drgary »

Case, I think a hot charge, slow finish will work better with this coffee. The hot charge will drive heat into the center of the bean. A ramp that starts fast will preserve sugars. Backing off heat approaching first crack will help you glide into a slow finish without a crash or flick that would reduce sugars and acidity. Extending the time of development while keeping the temperature from going too high will develop the berry flavors without degrading them.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

Case17

#17: Post by Case17 »

drgary wrote:Case, I think a hot charge, slow finish will work better with this coffee. The hot charge will drive heat into the center of the bean. A ramp that starts fast will preserve sugars. Backing off heat approaching first crack will help you glide into a slow finish without a crash or flick that would reduce sugars and acidity. A Extending the time of development while keeping the temperature from going too high will develop the berry flavors without degrading them.
Thanks Gary!
I had been thinking to do something similar, especially making sure to focus on air flow control per the general low-drying/medium-malliard/high-1C concepts. However, maybe I should go back to higher charge temps as well.

At some point with Eth DPs, I decided to lower my charge temps (had been using 230-250C for 350g batches, but now more like 200-220C), hoping to stretch the Malliard phase. It seemed to help with last years Keramo (what I was practicing on at the time)... I can get nice acidity and moderate tart fruits... but still the fruit could be more pronounced.
But, the other way to do it is to charge high and then really start lowering the heat application rate by lower heat and increasing airflow gradually. I'll give it a try. I'll definitely try this out.

I do agree that in that last profile the development time is too low. I was trying on purpose to keep the drop temp low. As you suggest, to both keep the drop temp low and the development time reasonable, then I need to stretch the roast longer but need the RoR high in the beginning and low at the end. The concept I have been concern with is that when you get to really low RoR, at what point is it considered baking?

pcofftenyo

#18: Post by pcofftenyo » replying to Case17 »

Gary's roast was interesting in that the charge to TP temp change was 190F which I've not tried recently. What do you do control-wise to cause that: Heat obviously off but to you crank fan to suck out heat? Then what are your heat and fan changes?

Case: I'm not familiar with a Bullet but yeah, I'd peg that as being somewhat baked based on the profile. Flat cup, indistinct.

User avatar
drgary
Team HB

#19: Post by drgary »

I do a 1.5 minute soak to start, which means that heat and fan are off. The soak drives a lot of heat into the beans without scorching. Then I start heat and fan nearly simultaneously and have the fan just high enough to support new oxygen intake for the flame and to remove chaff. Higher fan in my roaster tends to bake the coffee because the air is removed to a cyclone chaff collector. I use enough heat so the whole system has enough momentum that I can back off the heat in anticipation of first crack and development. I leave the fan constant and set the drum speed so the beans tumble at about a 45 degree angle. That way the beans have drum contact but don't scorch. My drum is perforated, which may be one-of-kind for a propane North TJ-067. Henry Chang suggested that perforated drum and suggested that this would deliver more heat via infra-red radiation. It may also reduce scorching by slightly reducing contact. This roaster is built of thick steel and well insulated. Before the first roast of the day, it takes 20 minutes of preheating.

The apparent large temperature swing between my bean temperature at charge and turnaround is probably instrumental. The beans are charged at room temperature, then my probe needs to catch up.

Each roaster is different, so there's a learning curve before developing fine control. I'm just getting there and am very excited after learning bits and pieces over the years. I used to have a Hottop, which needed more anticipation of heat changes, so the fan was more important in controlling energy to the roast. There wasn't as much air exchange. Fan is also more critical with my heat gun/bread machine, where turning up airflow to the heat gun drives more heat into the coffee and doesn't cause much baking because the air is well contained. I've never tried an induction roaster like the Bullet, so I don't know how much the fan removes air from the system, which would have greater potential for baking with more air exchange.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!