Filter basket

temperature sensor

"I wonder why and how you measure the filter temperature."

"Let me tell you about the temperature of the filter basket."

Q. Why do you measure the temperature of the filter basket?

A. "Extraction temperature" can be defined as "the temperature at which water from the machine, coffee puck, and filter basket are influenced by each other when extracted." The extraction temperature has a considerable impact on taste, aroma, and yield. If you can observe that the extraction temperature is constant, it will be an important indicator of extraction consistency.

Q. Can it show me if the extraction water temperature of the espresso machine is constant?

A. There are specialized instruments that measure the temperature of the machine's extraction water. (Structure where coffee cannot be extracted)

The temperature of the machine's extraction water can also be measured with the Velka filter. (It's a little more uncomfortable.) Warm up the Velka filter with boiling water as much as possible, insert an orifice pad ™ in the filter basket, apply pressure on the machine, and check the figure after 20 seconds.

Q. During extraction, can I see the temperature of the coffee puck?

A. Previously, there was a 'coffee puck temperature instrument'. The instrument has a probe-type temperature sensor installed in the center of the filter basket. However, the sensor affects the flow of coffee, making normal extraction impossible.

The filter temperature sensor of the belkafilter measures the 'temperature of the filter basket' on the outer side of the filter basket, so it shows the outer temperature, not the center of the coffee puck. In a typical extraction, the central and outer temperatures of the coffee puck are not the same. However, only the outer part temperature of the coffee puck can be used to estimate the extraction temperature.

Belkafilter is the first product to measure the temperature of the filter basket and estimate the extraction temperature through the temperature of the outer part of the coffee puck.

Q. During extraction, how does the temperature of the coffee puck actually change?

A. At the beginning of extraction, the temperature of the coffee puck rises a little slowly even when hot water comes out of the machine. At this time, the temperature rise rate of the central and outer parts of the puck is different because the flow of extraction water through the coffee puck changes. For example, at the beginning of the extraction, if the extraction water flows to the outside of the coffee puck and then gradually flows more into the center, then the outside temperature of the coffee puck rises first and then the center temperature rises. This happens depending on the condition of the packed coffee, even if the temperature of the extraction water in the machine is constant.

Q. How can I use the 'Filter Temperature Sensor' of the Belkafilter?

A. You can set criteria for extraction temperatures and quantitatively evaluate continuous extraction consistency.

You can also use the orifice pad to check the actual temperature of the machine's extraction water and manage boiler performance.

TargetIndicatorTo check indicator
Managing extraction consistency
Consistancy of the extraction water flow the coffee puckCheck filter temperature during extract
Managing extraction consistency
Filter preheating temperatureCheck filter temperature after extract
Management of machine temperature performance
Machine extraction water temperature measured in accordance with SCA regulationFilter preheating ⇢ Use 'Orifice pad™' ⇢ Measured by filter temp. after 20sec

"Can you show me how to use it?"

"First of all, check the temperature of the water on your machine."

After warming up the Belkafilter sufficiently, operate the machine with the orifice pad™  on without coffee. The actual temperature of the extraction water on the machine can be determined by the figures displayed 20 seconds after the maximum pressure has been reached. You can see if the temperature displayed on the machine is the same as the actual temperature, and if it remains in that state, it rises, or falls.

Repeat the same measurement several times to see how constant it is.

"This is how you manage machine performance."

If you measure and record each group of the machine in the above way, you will be able to manage the aging of the boiler by checking it regularly.

"Now, let's extract it as usual."

Try to extract as consistently as possible with a Belkafilter as usual.

Later in the extraction, you can see at what temperature the outside of the coffee puck stabilizes.

When coffee beans are ground thicker or finer, you can see how the outside temperature of the coffee puck changes.

If the same filter temperature graph is consistently reproduced in several identical tests, it will be possible to view it as a coffee puck outer temperature reference for that extraction and determine the temperature consistency in the subsequent extraction.

"How is the measurement performance?"

"Please check the accuracy."

Q. How much does the filter basket temperature reflect the temperature outside the coffee puck? During extraction, how different is the temperature outside the coffee puck from the central temperature?


temperature sensor

"Let me tell you about the temperature of the filter basket."

Q. Why do you measure the spout temperature?

A. This is to estimate the temperature of the espresso.

Q. Where is the sensor?

A. Near the drain leading to the spout, there is a gathering place for all the coffee extracted, there is a submerged sensor probe, and at the end is a temperature sensor.


TargetIndicatorMeasurement method
Managing extraction consistency
Consistency of extracted espresso temperatures
Check the coffee temperature at the end of extraction