We tested the Stone espresso machine. This heat exchange machine is slim, one of the most affordable, and convinced us in our tests. You can find out more in the video. Temperature curves and further information on the Stone Espresso can be found below.
Design and First Impression
Upon unpacking the Stone Espresso, its appearance immediately catches the eye. Our version of the Stone has black metal panels, which are removable and can be replaced with other design elements to customize the machine. There are stone panels, as well as wooden slats. This allows everyone to make the machine their own.
The machine is extremely compact and fits well on any work surface with only 22 cm width, a depth of 43.5 cm (without portafilter; 55 cm with) and a height of 41 cm. The machine weighs 20.5 kilograms.
Overall, the Stone Espresso leaves a high-quality impression, even if some parts that shine on the outside are not completely convincing on the inside.
One such example is the drip tray. It holds only 400 ml. This is really small and disappointing, because from the outside the front of the machine actually looks relatively wide. Unfortunately, the internal part led the testers to say that it looks more like a pigeon water dish.
The start and stop operation of the machine is unique. Stone Espresso shows a characteristic in-house development of the brewing group here. It has a brew lever above the group. The plastic square is twisted to start and stop. There is no volumetric dosing or programming, but only a manual brew, similar to Faema E61 brew groups. However, it feels good and works perfectly. The only drawback: the square on our machine twists slightly beyond the flush edge of the brew group when stopping the shot, which doesn't look great and might trigger the "urge to twist back" in those who appreciate order.
Stone Espresso's Own Brew Group
The Stone Espresso's brew group is equipped with a 200w heater, ensuring a quick heat-up time. We measured a heat-up time of 9.30 minutes, which is very fast compared to many heat exchange espresso machines. Subsequently, the temperature stability in the Kaffeemacher temperature protocol is good to satisfactory, with a tendency to rise towards the end of the shot. We measured a standard deviation of 1.22 degrees over 5 shots. This places the machine in the range of machines like the Lelit Elizabeth, Lelit Victoria, or Profitec Pro 300.
However, the performance of the Stone Espresso completely breaks down in the WBC protocol, and we see a standard deviation of 2.89 degrees over 14 shots. Here it can be clearly stated:
- Few shots: it's fine after 9.5 minutes and then the Stone Espresso's temperature is solid.
- Many shots: then the temperature cannot stabilize and fluctuates and rises continuously. Not good at all!
However, for the price range and home espresso use, the WBC protocol is not designed. Nevertheless, some inexpensive machines perform well here, which is why we conduct the test. If you make a few shots of espresso per day at home with the Stone Espresso, you will have no problems at all!
Good Espresso with the Stone Espresso
Our espressos tasted very good. Especially more classic coffee blends and also Italian-style espresso deliver very satisfying results on the Stone Espresso.
Neither with the temperature nor with the flow rate or pressure did any irregularities show up. 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 when it comes to preparing espresso!
Cappuccino and Co. with the Stone Espresso
Frothing milk with the Stone Espresso heat exchange espresso machine is a process that requires a little practice, but certainly delivers satisfying results. Thanks to the heat exchange system, the machine can simultaneously extract espresso and froth milk, which is a big plus for cappuccino and latte macchiato fans.
The machine is not a frothing miracle. It could use a bit more pressure. It takes 40 seconds in our benchmark test to heat water in the milk jug. This is normal heat exchanger behavior.
However, with the right practice and a little familiarization, even beginners and experienced home baristas will get the hang of it.
We frothed creamy milk foam that is excellent for cappuccinos and other milk coffee variations. The Stone Espresso thus proves that it offers solid performance for its price when it comes to milk foam.
Energy Consumption of the Stone Espresso
Despite the fast heating time, the energy consumption of the Stone Espresso is rather in the lower-middle or more classic range for heat exchanger espresso machines. This is mainly due to the fact that we always heat the 1.7-liter steam boiler. This is typical for heat exchanger espresso machines, as the brewing water is heated by passing through the steam boiler. And since the steam boiler has its size, and the heating of the brew group also demands power, we come to 0.24 kWh for heating time and 5 double shots. For comparison: with many thermoblocks, we are in the range of less than 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 have performed very well in our large heat exchanger test as one of the most affordable and best espresso machines in this segment.
More on power measurement and energy consumption.
