Precise control of brewing temperature is a critical factor for the quality of espresso. To reliably measure this temperature, the Scace 2 was developed as a temperature measuring portafilter – a precision measuring device that primarily measures temperature, but optionally also pressure, directly at the brew group. We use the Scace 2, which we have had adapted for various portafilter sizes. Currently, 7 Scaces are in use in our two coffee academies and in the test laboratory. In addition, we use two other temperature measuring devices for espresso machines to cross-check the behavior of different portafilters and machines. One of these portafilters has, in addition to the temperature probe, a pressure and flow recording that can be digitally captured.
Principle of temperature measurement in the portafilter
Temperature measurement in the portafilter is complex, as it must be carried out under realistic brewing conditions. A simple thermometer in the water flow is not sufficient, as the extraction and the typical conditions that occur during a classic extraction in the portafilter must be simulated. These include water flow, pressure, and the so-called headspace, i.e., the space between the coffee puck and the shower screen. The Scace 2 solves this problem by:
- Positioning a Type T temperature sensor in the correct place
- Simulating the coffee puck with a special rubber insert
- Mimicking the correct water flow
Compared to coffee, there are still deviations, as the rubber insert, for example, cannot absorb brewing water. This must be taken into account when calculating the water quantity.
The Scace 2 Thermofilter in detail
The Scace 2 is an advanced measuring instrument with the following features:
- Precise temperature measurement: It measures temperature to within 0.1°C.
- Fast response time: The temperature sensor responds in less than 0.25 seconds.
- Integrated pressure measurement: A glycerin-filled manometer displays the brewing pressure. There are Scaces with and without pressure measurement.
- Simulation of the coffee puck: A plastic insert with low thermal conductivity simulates the resistance of the coffee grounds.
Application and benefits
The Scace 2 is inserted into the brew group like a normal portafilter. It is suitable for:
- Commissioning and maintenance of high-quality espresso machines
- Quality control in coffee shops and roasteries
- Precise machine settings for reproducible results
- Espresso machine tests and comparability of espresso machines (WBC protocol, Kaffeemacher protocol).
Special production of the Scace 2 for Quick Mill espresso machines with three bayonet lugs.
Technical Limitations
- Compatible with most commercial E61 brew groups as well as 58mm brew groups such as La Marzocco, Rancilio, Rocket, ECM, Maro, etc.
- For testing various other espresso machines, we have had special portafilters in sizes 53, 54, and also 57 custom-made, which function according to the same principles. In this way, we have measured inexpensive machines such as the Delonghi Dedica, for example.
- Requires a digital thermometer with a T-type connection for temperature display.
Our test equipment collection has escalated slightly in recent years.
Portafilter for recording flow, temperature, and pressure conditions in the portafilter.
