Precise control of the brewing temperature is a decisive factor for the quality of the espresso. To measure this temperature reliably, the Scace 2 was developed as a temperature-measuring portafilter—a precision instrument that primarily measures the temperature, and optionally the pressure, directly at the brew group. We use the Scace 2, which we have had adapted for various portafilter sizes. We currently have 7 Scaces in use across our two coffee academies and our test laboratory. In addition, we use two other temperature-measuring devices for espresso machines to verify the behavior of different portafilters and machines. In addition to the temperature probe, one of these portafilters features pressure and flow recording, which can be tracked digitally.
Principle of temperature measurement in the portafilter
Measuring the temperature in the portafilter is complex because it must take place under realistic brewing conditions. A simple thermometer in the water flow is not enough, as the extraction and typical conditions that occur during a standard shot in the portafilter must be simulated. This includes water flow, pressure, and the so-called headspace—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 location
- Simulating the coffee puck with a special rubber insert
- Imitating the correct water flow rate
Compared to actual coffee, there are still deviations, as the rubber insert cannot absorb brew water, for example. This must be taken into account when calculating the water volume.
The Scace 2 thermofilter in detail
The Scace 2 is an advanced measuring instrument with the following features:
- Precise temperature measurement: It measures temperature with 0.1°C accuracy.
- Fast reaction time: The temperature sensor reacts in less than 0.25 seconds.
- Integrated pressure measurement: A glycerin-filled manometer displays the brewing pressure. Scaces are available with and without pressure measurement.
- Coffee puck simulation: 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 adjustment for reproducible results
- Espresso machine testing and comparability (WBC protocol, Kaffeemacher protocol).
Custom-made 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.
- To test various other espresso machines, we have had special portafilters in sizes 53, 54, and 57 manufactured that operate on the same principles. In this way, we have also measured affordable machines such as the Delonghi Dedica.
- Requires a digital thermometer with a Type T connection for temperature display.
Our collection of test equipment has escalated slightly over the last few years.
Portafilter for recording flow, temperature, and pressure conditions in the portafilter.
