Fan preview copy
Fan Preview is a function to check the bean circulation before roasting. It does not heat, but only activates the fan to check the movement of the beans in the roasting chamber.
Operation is easily accessible from the "≡ (Menu) button" on the main unit.
Why Fan Preview is Important
In Kaffelogic, one of the important factors affecting the quality of roasting is "proper bean circulation."
Normally, the fan is automatically controlled based on calibration, but
- Differences in bean density
- Changes in batch size (input amount)
may result in less than ideal circulation. By using Fan Preview, you can check the condition before roasting and make adjustments as needed.
How to check bean circulation
Follow these steps to perform a circulation check using Fan Preview.
- Weigh 120g of green beans and put them into the roaster.
- Attach the chaff collector.
- Select the K-logic Classic profile.
- When "Press ⏵ now for fan preview" is displayed, press the ⏵ button.
→ The fan will activate. - The display will show "120g" and "14700 rpm". If not displayed, adjust to these values using the +/- buttons.
- Check the bean circulation status.
Ideal Fan Level
- The ideal state is for the beans to circulate gently.
- Pay particular attention to whether the beans in the central part are slowly rotating and exchanging places.
Fan level is too strong
Fan level is not enough
If bean circulation is not observed in the center, recalibration is necessary.
How to deal with weak circulation
If sufficient circulation is not obtained, adjust as follows:
① If the BOOST KIT has not been updated
First, reduce the input amount and check the circulation status. Perform Fan Preview while reducing the current input amount by 10g at a time.
Example: 120g → 110g → 100g
By adjusting gradually,
you can find the optimal point where the beans circulate smoothly.
Reducing the input amount often lightens the movement of the beans and improves circulation.
※Nano7 is based on a calibration setting with 120g as the standard. Therefore, the circulation status may change with input amounts other than 120g, and it is important to confirm and fine-tune using Fan Preview.
② When using the BOOST KIT function
If you are using the BOOST KIT function, you can increase the fan speed by increasing the roasting amount setting.
Example:
120g → 130g → 140g
Since the fan level automatically increases according to the input amount, a stronger airflow is generated, leading to improved circulation.
③ Final check
After adjustment, perform Fan Preview again to check if:
- the entire surface of the bean mass is moving
- the central part is moving well in particular
Please check.
Concept when using BOOST KIT (Important)
The Fan Preview and adjustment methods described above are based on a calibration setting with 120g as the standard.
When using the BOOST KIT, it is possible to roast with a larger batch size (e.g., 180g), but in that case, it is necessary to correctly understand the relationship between the fan setting and the input amount.
■ Basic Rule
Ensure sufficient circulation by running the fan at a setting value greater than the input amount.
■ Specific Example (using BOOST)
Depending on the type of beans to be roasted, first use Fan Preview to check the appropriate fan level based on 120g.
Example:
If 120g of green beans are loaded, and the circulation is weak at the 120g (14,700rpm) setting, requiring approximately +20g of airflow.
→ Change the roasting setting to 140g (15,387rpm)
→ Perform Fan Preview with the actual input amount remaining at 120g.
If circulation is good in this state, the appropriate fan level for those beans is "set to +20g for an appropriate 120g".
■ When roasting with 180g (using BOOST)
When inputting 180g, an even stronger airflow is required based on the correction value confirmed above (e.g., +20g).
→ Set to 200g (approx. 17447 rpm) and roast with 180g input.
This stabilizes the overall bean circulation.
※Before roasting, perform Fan Preview to check the circulation of the green beans.
■ When using Studio
When using Studio, it is necessary to incorporate appropriate fan settings when creating a profile.
Refer to the profile creation guide (under construction) for details, and register and operate the created profile on Nano 7.
■ Key Points
- Fan Preview is a 120g reference check tool.
- In actual roasting, optimize circulation by intentionally adjusting the input amount and set values.
- Especially for large capacities (150g or more), this adjustment greatly affects roasting quality.
What is the optimal state?
The goal is to find the "minimum fan level" that causes the entire surface of the bean mass to move.
If the fan is too strong, it leads to unnecessary heat escape and unstable behavior, and if it is too weak, heat accumulates, affecting the reproducibility of roasting.
Proper circulation is the basis for stable roasting and clean flavors.