Hi guys,

Rookie Quest driver would like to roast drinkable Yirgacheffe. Have read and read and read but there are way too many strategies with charge temp varying from around 210 all the way down to 150-160 and consequently different length of roasting phases. I love Misty Valley and bought some green beans (wet processed, moisture: 11.3%) aiming for nice light espresso roast. Anyone out there with some guidelines or strategies on this variety? So far I have achieved less and less grassiness. Only have analogue BT probe and manually logging temp every 30 seconds. Will get Phidgets and thermocouples shortly. Think I will try this strategy downsized to the Quest:

PS. Would also be interested in Kenyan Ngerwe too Thanks very much.

http://kostverlorenvaart.blogspot.com/2 ... roast.html

The coffees grown there are mostly of very high density and tolerant to high charge temps. I've roasted natural yirgacheffes charging at 210 and also dropping them at the same temperature. For me, a total roast time of 11:30 worked really well, using much air flow starting early in the roast (120 degrees) if they have a lot of chaff. Furthermore I advice you to aim for a developement time ratio of around 1:30-2:00. Taking too long would bake the coffee rather than further roasting it. If you cannot roast as quickly as this with your setup I'd suggest lowering the batch size. Good luck

EDIT: Lets say that your temps are on average 40 degrees below mine on my machine, so just subtract 40 from what I wrote.

I like to roast high quality Yirg's pretty fast, which emphasizes their clean citric & floral flavor profile. My most recent roast, of a washed coffee from Buufata Konga, was charged at 416F. I got to 300F in 3 minutes, spent another 2:45 going to first cracks, and then had about 1:40 of development time (22.5% of the overall roast time), going from 382F first-crack-start-temp to finish at 399F, with a 7:25 overall roast time.

Provided you push enough energy into the beans early on and then wait to drop the beans until after astringent smells have dissipated, you shouldn't get any grassiness, even with a fast roast like this.

You might want to read through some articles over at Coffee Shrub. I found them quite informative.

http://www.coffeeshrub.com/shrub/conten ... amentals-0

I did an episode of Roast Profile Development focusing on a really nice Yirgacheffe coffee a few years ago. No grass, did rather well as espresso.

[creative nickname] wrote:I like to roast high quality Yirg's pretty fast, which emphasizes their clean citric & floral flavor profile.

Ditto. I spent six months trying to figure out why Yrgs and Sidamostasted better air roasted than drum roasted, before my d'oh moment.

Guys thank you so much for the help! I finally received my Phidgets 1048 and two 5mmx5cm thermocouples (will swap these for 3mm ones later this month) and started using Artisan, too. My roaster is a stock Quest 3 MkII with the trier on the right and always running fan. 220v model and Power on the graph represents 0-5.5A (max) and 0-8 fan

Here's one of my first roasts of the Yirgacheffe Gelana Abaya Grade 1 (Natural) beans. Although it came out surprisingly good, I will make the roast a bit faster so I can get a more dynamical first crack. Any comments on the celsius/min ROR in each stage or on anything I could improve or try out on the next roast? I will aim for an even faster finish and a bit more slowdown right before/during first crack. Well need to plan that because this electric roaster takes 20-30 seconds to effectively react to knob turns.

Many thanks, Laci.

N3Roaster wrote:I did an episode of Roast Profile Development focusing on a really nice Yirgacheffe coffee a few years ago. No grass, did rather well as espresso.

Neil this has been really nice and most educational. It is totally logical and makes complete sense. Problem is I can't scoop out enough that fast from the tiny Quest "toy" roaster Will try to reproduce previous roast and drop at different development percentages. Even a couple of trier uses will turn drum temperature upside down hahahaha

Hey and just out of curiosity, how do you apply the chosen test batch (2lbs?) profile to a production batch so you have the same taste profile on the 12kg (or whatever optimal) load you use for production? Thanks heaps!