Espresso Coffee Machines

How Espresso Coffee Machines work

What is Espresso and how do espresso coffee machines work? Espresso is a shot of coffee made by espresso coffee machines from forcing 1.5 ounces of water through tightly packed coffee granule. From this results a dark brown liquid which is slightly thicker than the consistency of water. In addition you will also get a small amount of foam formed similar to foam formed on the top of a beer.

Many factors influence the taste, aroma and texture of a shot of espresso; these things are – the temperature of the water, the water pressure, and the tightness and fineness of the coffee. The coffee granules for espresso are ground much more finely than that for normal coffee this helps to capture much more flavour from the bean in the shot.

Simple espresso coffee machines

A simple espresso machine packs coffee granules into a funnel shaped sieve allowing for drainage at its bottom. Water in placed into a reservoir within the machine and is heated via a filament. Pressure builds up within the water and the only way for this water to escape is through the open end of the sieve. The water travels through a tubing interface and toward the sieve relieving pressure and passing through the sieve.

Disadvantages to this method are that the water must reach a certain pressure which is derived from the temperature of the water, this can mean that the water exceed the ideal temperature to make espresso, about 90oC, and spoil the cup. However temperature regulators can be used to ensure the water is at the optimum level.

The Pump Machine in Espresso Coffee Machines

Another type of espresso coffee machine is the pump machine. It is comprised of several elements: The reservoir holds the cold water ready to be pumped through the system; the pump draws the water from the reservoir and through to the heating chamber. In the heating chamber the water is heated to the ideal temperature.

There are several types of heating chamber however the cheapest and most widely used is a solenoid, the design of which is similar to that of a bulb. From here the water is passed through to porta-filter, this is where the coffee granules lie in wait for the impending water. The water draws the flavour texture and aroma from the granules as it passes through and finishes in a cup placed under the filter.

Making a Shot of Espresso with Espresso Coffee Machines

Making a shot in a pump machine is relatively easy, one shot of espresso granules are placed in the porta-filter which is then twist-locked into place. The machine can then be turned on and an indicator light will flash to make you aware that the water is being heated.

Once the water is at the correct temperature the light will turn off (depending on the model) at this phase a simple press of a button should then initiate espresso coffee machines to start dispensing the water through the ground beans and into your cup.