Received my 10 lbs yesterday and put in 3 roasts today.
I roast on the Huky 500T with a charge size of 375. I went up to 400 for the R & L because I have so much of just one coffee. I didn't realize I would have to adjust for this in a pretty significant way, so there are a couple of hiccups on the roast curve. Anyway, here it goes:
I wanted to understand how the impact of different heat levels on the development of washed Ethiopian coffees. There are three approaches I'm testing for:
1) Full heat, short development: The idea is to push the coffee as hard as can during development, but shorten the overall development time. I like to approach of full development with limited sugar caramelization for maximum fruit/florals and sweetness with little to no roast flavors.
2) Low heat, elongated development: There is this fear in my head that high heat post 1C will burn off florality and aromatics. So why not go for what many roasters do, which is try to use the lowest possible RoR post 1C that still provides full development.
3) Somewhere in the middle.
My first roast:
The RoR crashed at 1C, but I did not back down from heat at 95% (4 KPA on the Huky). The 1C was insanely uniform and loud, like a machine gun. I believe that the RoR crash is simply the intense exothermic reaction overloading the probe. It does not recover because I dropped the coffee before the RoR could pick back up.
Same situations as the first roast, except I incorporated a higher charge temp in order to compensate for the higher charge weight & density of this coffee. I also dropped the heat earlier going into 1C vs. the first Roast (where I didn't drop the heat at all. The 1C happens a little later, and in a more controlled way, albeit the crash still happens (all the while the 1C is rolling like crazy). It's a false crash, just like the 1st Roast.
I wanted to speed up the dry, so I bumped up the airflow a little bit (55 up to 60 on the variac). This seems minute, but the difference is pretty huge. I also lowered the heat to 3.5 KPA 10 degrees before anticipated 1C. Then lowered to 3 KPA when rolling 1C started. I decided to try and finish 1C on this roast to see how it compared to the other two roasts. The result seemed to have a significant roast characteristic (which may not be bad). But since I'm looking for purer fruits/florals, it may not be the roast I prefer...
Cupping notes to come later...