Continuing with the theme of using more complicated profiles for roasting we took this Classic Mandheling to City+ and a final temperature of 436 degrees, final roast time was an average of 16 minutes. To try and develop more character in the cup we started the roast off with the gas throttled down a bit until the beans began to show some yellowing. Then the heat was brought up to full blast until the thermoprobe read 370 degrees. This was about 10 minutes into the roast, then we dropped the heat back significantly to draw out the roast. Hopefully this will help maintain the structural integrity of the bean imparting more complex flavors and balance to the cup. We brewed up a pot today and it shows promise, we'll see how it tastes after a full day of resting. The Liquid Amber was similarly profiled to build up a healthy charge on the front side of the roast and then draw out the already extended first crack which started at 406 and continued all the way until the 430 degree mark. For this espresso blend we favor a Vienna or French roast level so final temp was 460 degrees and total roast time was an average of 16:30. The batches were dumped well into second crack and continued to snap and crack as the coffee cooled in the tray. We'll pull some shots late today or tomorrow after the coffee has had plenty of time to rest and see how we did. The Panama decaf was roasted to City+ with a final temp of 420 degrees and roast time of 15 minutes. For this decaf I built up the heat in the drum a little more slowly before lowering the gas to create a gentler first crack.
Sweet Maria's Weblog
We just received the new crop lot of Rwanda Duhingekawa Women's Cooperative coffee from this Fair Trade group, and it has the same balanced, slightly citric profile as last year's great delivery. Read more about their unique group here. We also have the classic Sulawesi Grade One Toraja, a traditional semi-washed Indonesia with great bean preparation (few defects, and oddly, almost no chaff when roasting). And I am off to the SCAA conference in Minneapolis. Actually, Josh and Derek are coming too, so watch out Minnesota! Maria and the crew are holding down the fort and keeping the orders rolling.
Wow - this Brazil is such a beautiful coffee, dark opal green color, remarkable preparation, fantastic to roast in the Probat. I used a roast profile where I reached 1st crack in 11 minutes and dropped the heat at the first pops to extend the time until target temperature of 430 f was reached. The Probat has a lot of steel in the drum and end plates, meaning that there is a lot of conduction of heat to the coffee, so you can drop your flame and "cruise" quite easily in this roaster. That's not the case with roasters like the behmor, which is mainly radiant and convective heat, or air roasters that are pure convection. But the idea is the same, and roast profiles can be matched between different types of machines. It's too early to really cup the coffee, but my goal is to preserve brighter tones in the cup, which should emerge as the cup cools down in tasting. The Colombia decaf was fairly light but colored quite heavily and had a loud pop. I think we'll see oils emerge even though this is a fairly like 430 f roast, but that's a way in which decafs can be weird. The Moka Kadir was a 460 f roast that I slowed considerably at the finish. Should have a lot of chocolate tonality!
New crop Central American lots are starting to come in. The first new crop Guatemala is from Fraijanes: Guatemala Finca La Florencia 100% Bourbon, a classic, balanced old-cultivar cup with surprisingly dense body. We also have a very limited amount of Jamaica Blue Mountain. Okay, not really. The JBM from Jamaica has cupped out flat as a board this year, but we have Hawaii Kowali Blue Mountain (JBM Cultivar) grown by this excellent small family farm in Kona.
I decided to stay a little lighter on the Rwanda Gkongoro Nyarusiza than I might have, based on some test roasts I did. I roasted pretty much full heat until the very beginning of 1st crack; average of 1:30 minutes, 403 f. Then I brought the flame down to the minimum amount I could to draw out the roast time and yet not too little to stall the roast. This is critical, because when coffee goes exothermic during 1st crack, you must be providing enough heat to the roast charge in order to keep things moving along. It makes sense in terms of pyrolysis in other types of cooking, and it makes sense in coffee. The key browning event in coffee is the Maillard reaction, an interaction between amino acids and reducing sugars, and it's the same that occurs in the browning of beef! And it definitely wouldn't be good BBQ technique to achieve a nice brown meat by letting it go cold when it's half done, then crank up the flame again and finish it. Anyway, the Probat takes care of warm-up phase with the roasts quite well - we don't have to diddle with the air and gas controls from the green-to-yellow-to-tan phases. We do make adjustments for the finish phases of roasting, and this is true with the Costa Rica La Libertad decaf this week, because you can easily race to the finish temp. of 428 f on this with too much "momentum". So I also back off the flame severely at the start of first ... in fact I make sure with decafs that I approach first gingerly. Classic Italian is our darkest roast for espresso, darker than Puro Scuro and Monkey and Moka Kadir. That said, we are still on the light side compared to other roasters. If you want shiny black pieces of carbon, look elsewhere. The fact is, we put such nice coffees in our blends, I just can't abuse them with roasting until everything tastes like charcoal. 463 f is the highest finish temperature on the Classic, and it does depend a little of the atmosphere and "speed" and which you approach 2nd crack. That's where you need the human in front of the roaster. In coffee, the numbers always DO lie, at least just a little bit. The thermocouple can shift a little, the air can be a little more humid, the gas valve can be set a tad more open or closed ... that's where an experienced roaster-person is so important.