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Java Master 2002 Coffee Roaster (view source)
Revision as of 07:21, 10 November 2022
, 07:21, 10 November 2022→Roast Profile
== Roast Profile ==
== Roast Profile ==
Roasting is determined by two parameters: hot air temperature and bean temperature. Hot air temperature is set on the left PID controller. It should be adjusted based on the bean weight to be roasted and the desired speed of roast, and is the temperature of the air entering the roast chamber. More beans require more heat to roast at the same speed. Target bean temperature is set on the right PID controller, and corresponds to the temperature of the air exiting the chamber. When this temperature is reached, the machine begins its cool down cycle. Note that this number is a significant underestimate of the actual bean temperature, but it provides an easily measured parameter for when to end the roast. This temperature can also be adjusted while the roast is in progress to prolong or end the roast earlier, but note that the PID controller takes several seconds to recognize the change.
Roasting Profiles refer broadly to important parameters and conditions of the roasting process. The roasting process is a process of caramelization and carbonization called a Maillard Reaction. Some important roast parameters include:
* Temperature beginning roast
* Temperature ending roast
* Rate of Rise in temperature over total duration and specific periods of roast
* ‘Development’ of roast at specific temperatures during specific sequences of the roast
* Total Duration of the roast
* Degree of ‘crack’ achieved in the bean (i.e. First, Second)
* Color achieved
* Speed of cooling
In general, coffee sugars are made accessible by roasting, but the caramelization process also reduces perceptual sweetness over roast time at a similar degree of roast. Additionally caffeine content lowers over time with off-gassing from longer roasts. Acidity also tends to lessen over time past CitY+ and into Full City/Second Crack, until carbonic acidity eventually raises in the darkest roasts. Roasters aim for a consistent rate of rise over time, just as with making caramel, so that the caramelization process does not stop and start haltingly, which will reduce perceptual sweetness as well and lead to uneven bean development.
Roasting on the Java Master is determined by two PID separate controlled parameters: hot air temperature and bean temperature. Hot air temperature is set on the left PID controller. It should be adjusted based on the bean weight to be roasted and the desired speed of roast, and is the temperature of the air entering the roast chamber. More beans require more heat to roast at the same speed. Target bean temperature is set on the right PID controller, and corresponds to the temperature of the air exiting the chamber. When this temperature is reached, the machine begins its cool down cycle. Note that this number is a significant underestimate of the actual bean temperature, but it provides an easily measured parameter for when to end the roast. This temperature can also be adjusted while the roast is in progress to prolong or end the roast earlier, but note that the PID controller takes several seconds to recognize the change.
Suggested roasting parameters:
Suggested roasting parameters:
We don't have experience yet with darker roasts. More data would be appreciated!
We don't have experience yet with darker roasts. More data would be appreciated!
Additional efforts are being made for us to be able to ‘log’ roasts as temperature over time graphs, in order to compare roast profiles for individual beans and measure outcomes.
== Safety ==
== Safety ==
