This component, typically a circular dial with a needle, displays the pressure within the brewing system of an espresso machine. A typical example shows a range from 0 to 15 bars, with the ideal espresso extraction pressure falling within the 8-10 bar range. This visual representation allows users to monitor pressure in real time during the brewing process.
Accurate pressure measurement is critical for consistent, high-quality espresso. Insufficient pressure results in under-extracted, sour, and weak coffee, while excessive pressure leads to over-extraction, producing a bitter, burnt taste. Historically, achieving the correct pressure relied heavily on experience and intuition. The introduction of this monitoring device provided a quantifiable measure, allowing for greater precision and repeatability, contributing significantly to the evolution of espresso preparation from a craft to a more controlled process.
