Steve's Ultimate Profiles 100g - Constantly Declining Fan Profile (Fan Cal 0.91)
Posted: Tue 20 Oct, 2020 5:35 pm
I believe these two profiles are my ultimate baseline / starting points for any style of roast, a culmination of everything I have done before.
One initial caveat is that I am using a 3 mm sheathed probe in place of the stock bare thermocouple.
The position is a little lower down in the roast chamber and just off centre towards the clean / cool side where no creosote forms. The temperature readings are directly comparable to the stock thermocouple going by other peoples testing and my previous profiles. The main difference I see and am assuming to be of great benefit is that because of the smoothing the 3 mm sheathed probe provides, this in turn feeds the PID with less chaotic readings resulting in a power profile being much smoother. Would need to do some repeated blind cupping against the same green coffee with the same profile roasted on a stock machine to see if there is any difference? If there is I am guessing it would be very small. From my ET / MET testing a smooth power profile literally translates into a smooth ET profile which is never a bad thing for any form of coffee roasting.
Through these MET / ET tests I also found that a constantly declining fan profile gave the most stable ET.
When the fan profile is static / flat and the moisture level changes in the bean mass this is enough to create significant changes in the fluid state which result in the ET plummeting which I can only assume creates baked roast defects. The attached screen shot shows both fan profiles in comparison to the Classic fan profile.
The start of the roast often seems to be overlooked but I have come to find that this where the overall roast development is determined, there is no fixing things later on and if the roast starts erratically then it is likely going to be under developed and or baked no matter what. I have found taking control of the first 1:00 - 1:20 by using a set "Power Profile Zone 1200 - 1270W" to be the greatest improvement out of anything I have tried previous. The pre heat function is clunky and ends roasts before they even really get going. By applying a set amount of heat for the first 1:00 - 1:20 and seeing what kind of curve is generated from that for a particular bean on the first roast, we can go into studio and fine tune the "profile" after for the PID to follow as close as possible. This fixed power start drives necessary early heat into the bean mass for proper development and then hands over control to the PID at a point where the bean mass is fully charged with heat, all the early moisture has been driven off and the beans have undergone significant expansion.
So far everything I have roasted has stayed under 1300W with ambient temps warming up. I am guessing with different atmospheric conditions and or roasting outdoors some people may still rub up against the limits of their power supply. I suggest getting a giant plastic tub and sitting the roaster inside that (obviously without a lid) which will create a mini local roaster environment.
These descriptions are cut and paste from the "about this file" in the roast profile.
CDFP = Cupping / Filter / Light all purpose roasts
0.7 - 0.9 cupping / very light filter
1.0 - 1.5 filter and general purpose
1.6 - 1.7 some very hard washed beans may benefit from slightly hotter finish for general use but after 1.5 most beans will likely be over developed
Grinder Fuji Royal R220 settings
Cupping 4.5
Filter 7.5
Water is a tweaked Third Wave Water recipe.
4L distilled water
1000mg Magnesium Sulfate
300mg Calcium Citrate
100mg Potassium Bi-Carbonate
DarkCDFP = Traditional espresso roasts
Designed with max level 5.9 ending around 20 - 30 seconds into 2nd crack start 17 - 17.5% weight loss depending on bean. Example is SHB washed Costa Rica - grade 1 commercial.
16.5g dose in IMS 16 -20g filter basket
Breville Dual Boiler with full flow profiling mods
Dot 9 Niche grinder
7 bar max pressure with 210g / 30 seconds water debit
88C brew temp
1:2 - 1:2.5 in 27 to 30 seconds
Water is a tweaked Third Wave Water recipe.
4L distilled water
1000mg Magnesium Sulfate
300mg Calcium Citrate
100mg Potassium Bi-Carbonate
One initial caveat is that I am using a 3 mm sheathed probe in place of the stock bare thermocouple.
The position is a little lower down in the roast chamber and just off centre towards the clean / cool side where no creosote forms. The temperature readings are directly comparable to the stock thermocouple going by other peoples testing and my previous profiles. The main difference I see and am assuming to be of great benefit is that because of the smoothing the 3 mm sheathed probe provides, this in turn feeds the PID with less chaotic readings resulting in a power profile being much smoother. Would need to do some repeated blind cupping against the same green coffee with the same profile roasted on a stock machine to see if there is any difference? If there is I am guessing it would be very small. From my ET / MET testing a smooth power profile literally translates into a smooth ET profile which is never a bad thing for any form of coffee roasting.
Through these MET / ET tests I also found that a constantly declining fan profile gave the most stable ET.
When the fan profile is static / flat and the moisture level changes in the bean mass this is enough to create significant changes in the fluid state which result in the ET plummeting which I can only assume creates baked roast defects. The attached screen shot shows both fan profiles in comparison to the Classic fan profile.
The start of the roast often seems to be overlooked but I have come to find that this where the overall roast development is determined, there is no fixing things later on and if the roast starts erratically then it is likely going to be under developed and or baked no matter what. I have found taking control of the first 1:00 - 1:20 by using a set "Power Profile Zone 1200 - 1270W" to be the greatest improvement out of anything I have tried previous. The pre heat function is clunky and ends roasts before they even really get going. By applying a set amount of heat for the first 1:00 - 1:20 and seeing what kind of curve is generated from that for a particular bean on the first roast, we can go into studio and fine tune the "profile" after for the PID to follow as close as possible. This fixed power start drives necessary early heat into the bean mass for proper development and then hands over control to the PID at a point where the bean mass is fully charged with heat, all the early moisture has been driven off and the beans have undergone significant expansion.
So far everything I have roasted has stayed under 1300W with ambient temps warming up. I am guessing with different atmospheric conditions and or roasting outdoors some people may still rub up against the limits of their power supply. I suggest getting a giant plastic tub and sitting the roaster inside that (obviously without a lid) which will create a mini local roaster environment.
These descriptions are cut and paste from the "about this file" in the roast profile.
CDFP = Cupping / Filter / Light all purpose roasts
0.7 - 0.9 cupping / very light filter
1.0 - 1.5 filter and general purpose
1.6 - 1.7 some very hard washed beans may benefit from slightly hotter finish for general use but after 1.5 most beans will likely be over developed
Grinder Fuji Royal R220 settings
Cupping 4.5
Filter 7.5
Water is a tweaked Third Wave Water recipe.
4L distilled water
1000mg Magnesium Sulfate
300mg Calcium Citrate
100mg Potassium Bi-Carbonate
DarkCDFP = Traditional espresso roasts
Designed with max level 5.9 ending around 20 - 30 seconds into 2nd crack start 17 - 17.5% weight loss depending on bean. Example is SHB washed Costa Rica - grade 1 commercial.
16.5g dose in IMS 16 -20g filter basket
Breville Dual Boiler with full flow profiling mods
Dot 9 Niche grinder
7 bar max pressure with 210g / 30 seconds water debit
88C brew temp
1:2 - 1:2.5 in 27 to 30 seconds
Water is a tweaked Third Wave Water recipe.
4L distilled water
1000mg Magnesium Sulfate
300mg Calcium Citrate
100mg Potassium Bi-Carbonate