Difference between revisions of "Java Master 2002 Coffee Roaster"
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== 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 | + | 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. |
| + | |||
| + | Suggested roasting parameters: | ||
Hot air temperature range is 530-575 F on the controller. For 1-2 lbs, it should be set close to 530 F. For 2-3.5 lbs, it should be set between 540-560. | Hot air temperature range is 530-575 F on the controller. For 1-2 lbs, it should be set close to 530 F. For 2-3.5 lbs, it should be set between 540-560. | ||
| − | Target bean temperature can be set between 370-445 F. This parameter determines the darkness of the roast. | + | Target bean temperature can be set between 370-445 F. This parameter determines the darkness of the roast. Suggested starting point: |
| − | + | * City (first crack complete) - 375 F. | |
| + | * City+ (significant development beyond first crack) - 380 F. | ||
| + | * We don't have experience yet with darker roasts. More data would be appreciated! | ||
== List of Currently Authorized Users == | == List of Currently Authorized Users == | ||
Revision as of 20:30, 5 November 2022
 | |
| Owner/Loaner | Theo Tetzlaff |
|---|---|
| Serial Number | 2736 |
| Make/Model | Java Master 2002 |
| Arrival Date | June 2022 |
| Usability | yes |
| Contact | Theo Tetzlaff |
| Where | General Area |
| Authorization Needed | yes |
| Hackable | no |
| Estimated Value | $7,500 |
| Host Area | General Area |
Description
This is a Java Master 2002 fluid bed coffee roaster, capable of roasting up to 3.5 lbs green beans per batch.
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.
Suggested roasting parameters:
Hot air temperature range is 530-575 F on the controller. For 1-2 lbs, it should be set close to 530 F. For 2-3.5 lbs, it should be set between 540-560.
Target bean temperature can be set between 370-445 F. This parameter determines the darkness of the roast. Suggested starting point:
- City (first crack complete) - 375 F.
- City+ (significant development beyond first crack) - 380 F.
- We don't have experience yet with darker roasts. More data would be appreciated!
List of Currently Authorized Users
| Qualified Member | Trained By | Date |
|---|---|---|
| Theo Tetzlaff | Owner | |
| Ryan Pierce | Danger Committee | |
| Carl Karsten | Danger Committee |
Green Coffee Bean Suppliers
- JavaMaster - Sells in 3.5, 10, and 40 lbs quantities
- Sweet Maria’s - Sells in 1, 2, 5, 10, and 20 lbs quantities
Maintenance
| Task | Date | Done by | Notes |
|---|---|---|---|
| Clean two exhaust thermocouples | 10/26/23 | Ryan | |
| Clean glass chamber | 10/24/22 | Theo and Ryan | Spot cleaning only |
| Clean upper duct | 10/24/22 | Theo and Ryan | Spot cleaning only |
| Vacuum clean air intake filter | 10/26/22 | Ryan | |
| Clean lower dump valve | 10/24/22 | Theo and Ryan | Spot cleaning only |
| Clean hot air thermocouple | 10/26/22 | Ryan |
Technical Details
The roaster uses a Watlow PID controller (on the left) to control air temperature. It outputs a process value (4-20 mA), which an Avatar Instruments power controller uses to change the power to the heater via SCR phase dimming. The Avatar supports 240 V but the heater itself only can handle 208 V. This machine was designed to operate on 208 V but JavaMaster confirms it can operate on 240 V with an adjustment. Originally, JavaMaster suggested we limit the PID to 70% max output power. But that resulted in unexplained oscillations in temperature typically +/- 30 F. The Avatar includes an optional feature to limit output voltage via the V-LIM trim pot. This was adjusted so 100% on the PID corresponds to 208 V as measured by a true RMS voltmeter. Moving this back to 208 V will require re-adjustment of this trim pot.