We have tested the Stone espresso machine. This heat exchanger is slim, one of the most affordable options, and really impressed us in our test. You can find out everything else in the video. You will find temperature curves and further information on the Stone Espresso below.
Design and First Impression
When unboxing the Stone Espresso, the look immediately catches your eye. Our version of the Stone has black metal panels that can be removed and replaced with other design elements to customize the machine. There are stone panels, but also wooden slats. Here, everyone can turn the machine into something that suits them.
The machine is extremely compact and, at only 22 cm wide, 43.5 cm deep (without the portafilter; 55 cm with one), and 41 cm high, it fits well on any work surface. The machine weighs 20.5 kilograms.
Overall, the Stone Espresso leaves a high-quality impression, even if some parts on the outside look better than what lies beneath.
One such example is the drip tray. It holds a mere 400 ml. That is truly small and disappointing, because from the outside, the machine's protrusion actually looks relatively large. Unfortunately, the interior leads the testers to say it is more reminiscent of a pigeon drinking bowl.
The start and stop operation of the machine is unique. The Stone Espresso features a characteristic proprietary brew group design here. It has a brew actuator above the group. The plastic square is turned to start and turned again to stop. There is no volumetrics or programming, just a manual draw like on Faema E61 brew groups. It feels good and works perfectly, however. The only drawback: our machine's square is turned slightly past the flush edge of the brew group when finishing a draw, which doesn't look nice and could trigger the urge to "turn it back" in orderly types.
Proprietary brew group of the Stone Espresso
The brew group of the Stone Espresso is equipped with a 200W heater, which guarantees a fast heat-up time. We measured a heat-up time of 9 minutes and 30 seconds, which is very fast compared to many heat exchanger espresso machines. Afterwards, the temperature stability in the Kaffeemacher temperature protocol is good to satisfactory, with a tendency to rise towards the end of the draw. We measured a standard deviation of 1.22 degrees over 5 draws. This keeps the machine in the same range as machines like the Lelit Elizabeth, Lelit Victoria, or Profitec Pro 30.
However, the performance of the Stone Espresso completely collapses during the WBC protocol and we fall to a standard deviation of 2.89 degrees over 14 draws. Here we can clearly state:
- Few draws: this works after 9.5 minutes and the temperature of the Stone Espresso is solid.
- Many draws: the temperature cannot stabilize and fluctuates and continues to rise. Not good at all!
But the WBC protocol is not made for this price range or for home espresso. Nevertheless, some affordable machines perform well here, which is why we conduct the test. If you make a few espressos a day at home with the Stone Espresso, you will have absolutely no problems!
Good espresso with the Stone Espresso
Our espressos tasted very good. Especially more classic coffee blends and also Italian-style espresso deliver very satisfactory results on the Stone Espresso.
There were no anomalies with either the temperature, the flow rate, or the pressure. With a good espresso grinder that is easy to adjust and an espresso that suits the home barista, the Stone Espresso is a good choice for preparing espresso!
Cappuccino and co. with the Stone Espresso
Milk frothing with the Stone Espresso heat exchanger espresso machine is a process that requires a little practice but definitely delivers satisfactory results. Thanks to the heat exchanger system, the machine can extract espresso and froth milk simultaneously, which is a big plus for cappuccino and latte macchiato fans.
The machine is not a frothing marvel. It could use a little more pressure. In our benchmark test, it took 40 seconds to heat the water in the milk pitcher. That is typical heat exchanger behavior.
With the right practice and a familiarization period, however, even beginners and experienced home baristas will get the hang of it.
We frothed creamy milk foam that is excellently suited for cappuccinos and other milk coffee variations. The Stone Espresso thus proves that it also offers solid performance for its price when it comes to milk foam.
Energy consumption of the Stone Espresso
Despite the fast heat-up time, the energy consumption of the Stone Espresso is in the lower-middle or rather classic range for heat exchanger espresso machines. This is mainly because we are always heating the 1.7-liter steam boiler as well. That is how it is with heat exchanger espresso machines, as the brew water is heated by passing through the steam boiler. And because the steam boiler has its size and heating the brew group also requires power, we arrive at 0.24 kWh for heat-up time and 5 double draws. For comparison: with many thermoblocks, we end up in the range of below 0.15 kWh.
Conclusion on the Stone Espresso
The Stone Espresso is a very good espresso machine in the heat exchanger segment, especially for its price. It would also have performed very well in our big heat exchanger review as one of the most affordable and best espresso machines in this segment.
More on the topic of performance measurement and energy consumption.
