What's the difference?
The Espresso Mechanism works by pushing pressurized water close to a boiling point through a “puck” of ground coffee to extract flavour from the beans and create a shot of concentrated or watered-down espresso. This mechanism can be manual or automatic, based on the type of machine, but the brewing time and fineness of the grind remain the same. The fineness of the grind is the most important factor with the Espresso Mechanism. If it’s too coarse it creates a weaker coffee, but if it’s too fine, the water will pass much slower, resulting in an over-extracted and bitter coffee.
Similarly to the espresso mechanism, the filter mechanism consists of pouring hot water on ground coffee into a container. However, the difference is in the type of pressure applied and the water quantity. To produce an espresso, the water is pushed through a stream, whereas, producing a filtered coffee requires only the effect of gravity, also known as an infusion process. A filtered coffee also requires a larger quantity of water compared to the espresso, and results in a less acidic drink, that highlight the more complex aromas, due to a slower absorption.