Non-Pump vs Pump Espresso Machines-Differences and Specifications
Non-Pump Espresso Machines
This type of espresso machine is considered a starter espresso machine or a gift espresso machine. Non-pump machines work with the steam pressure generated by the boiling water in a sealed chamber. It can create pressure of about 3 bars when the water is heated to above 200 degrees.
Step by step:
- Water is placed in a reservoir and the reservoir is sealed
- The water is heated by an element at the bottom of the reservoir
- As the water heats it generates steam
- The steam in the sealed chamber creates pressure which either forces water through the espresso grinds or the steam arm (if the valve is opened).
Most non-pump machines have enough capacity in the reservoir to brew 4 espressos.
- Non-pump machines are less expensive compared to other espresso machines on the market
- Great price point for a gift, or as an individual's first espresso machine investment
- The 200 degree water temperature needed to create steam pressure may scald the espresso
- Once used to make espresso it needs cool down before espresso can be made again
- Not enough pressure to make a true espresso with crema
- If used improperly it can be potentially dangerous. Specifically if one removes the filter holder or boiler cap before all contained pressure is released and the machine has cooled down
Another type of expresso machine contains what is known as the Thermo-Block system. This heats the water for espresso via a radiator instead of boiling the water in a reservoir like in the non-pump machines.
The Thermo-Block system allows you to heat the water to separate temperatures for brewing and steaming. This system will allow one to achieve crema and provide continuous steam for making cappuccinos and lattes.
Crema is the golden brown foamy extraction that is found on top of espresso; it contains most of the flavor. Eight bars of pressure are needed to produce this crema. Most pump machines produce 15 and above bars.
How does this system work and what is happening in the machine that allows it to work "better" than the boiler machines?
Water is poured into the reservoir of the espresso maker and then pumped out of the reservoir and flash heated on the coils of the Thermo-Block. The Thermo-Block looks like a radiator with thin, coiled pathways in which the water is heated just below boiling for brewing espresso or up to 275 degrees if steam is required.
Because there is a difference in the temperature required to brew espresso and steaming or frothing milk there will be a small lag in time between when the machine is ready for one function vs. the other.
- Since you don't have to wait for the machine to cool before opening the stopper you can continue to brew or steam
- Since the temperature achieved for brewing is a separate process from that needed to achieve the correct temperature for steaming the coffee is not scalded and potentially ruined
- Machine will allow a person accustomed to cafe quality espresso to achieve an espresso with true crema
- Has the shortest lag time between brewing and steaming in comparison to the boiler or pump-boiler machines
- The cost of a pump espresso machine may be prohibitive to some
- There is a small lag time between when waiting for the machine to reach the temperature for steaming after brewing