Steam, Piston, or Pump Espresso Machine?
If you want to begin producing espresso drinks at home, and you’re just learning about the different types of espresso machines, then you have to understand the distinction between these 3 different kinds of machines: the steam driven espresso machine, the lever and piston espresso machine, and the pump espresso machine.
The electric steam driven machine is the first one we’ll talk about. These are at the low end of espresso machines and cost the least. Steam pressure is what makes these machines work. Water in an airtight chamber is heated to boiling after which rapidly forced through the ground coffee utilizing steam pressure, and then right into a cup. The steam pressure produced by these kind of machines reaches about 1 bar, far below the benchmark pressure required to brew real espresso. These machines will typically include a steam wand for steaming and frothing milk. In my opinion these kinds of machines should truly not be regarded as espresso machines because the best they can do is create a strong cup of coffee.
Next we’ll talk about a manual machine that utilizes a lever and piston. Instead of utilizing pressure generated by steam, the pressure utilized in a manual lever machine to brew espresso is created by a piston that is attached to the lever, which, when pulled, forces the heated water through the ground coffee. There’s no automation with the lever device, and all aspects of the brewing process are completed without having benefit of any automation; this gives the lever device user total control over the brewing process which allows for any type of little adjustments to be made. Moving the lever up moves the piston up which then brings pre-heated water into the brew group. When the lever is subsequently pulled down it forces the hot water, under pressure, through the ground coffee. The phrase “pulling a shot” refers to this type of device, because you actually have to “pull” a shot. These lever and piston devices are capable of producing a pressure of 8-9 bar, the benchmark pressure of a genuine espresso drink.
A barista with many years experience utilizing one of these machines makes it look easy to make a perfect espresso. But there’s technique to be learned which more likely than not results in many, many failed efforts prior to mastering the skill. Personally, I’d choose a mchine that was a little simpler to use.
The final kind of machine that we’ll look at is the electric pump espresso machine. The electric pump machine utilizes a pump instead of a lever to move water through the system. Initially the pump is utilized to move unheated water from the reservoir into the boiler tank. When the water has been heated to the optimal temperature the pump then forces the heated water, under pressure, through the ground coffee within the brew group. With these devices you are able to set the exact temperature you would like the water to reach before the device rapidly pumps it through the coffee grounds. There are three kinds of electric pump espresso machines: The semi-automatic, the automatic, and the super-automatic espresso machine.
If you are a purist, then you may believe that a perfect espresso can only be “pulled” by the experienced hand of the veteran barista. But for those individuals who just want a simple, quick, and delicious espresso, the automatic espresso machine can do a darn good job of producing an exceptional, consistent cup of coffee.