When you pull a shot, the machine's tablet display shows an incredibly intuitive layout that does not require instructions. It visually charts two main components: a green curve, which indicates the pressure at the coffee puck, and a blue curve, which tracks the flow rate of the liquid passing through the puck.
The DE1 features various brewing recipes called pressure profiles. One classic profile is inspired by vintage lever machines; it initiates a gentle pre-infusion, shoots up to about eight or nine bars of pressure when brewing begins, and then slowly declines. This gradual drop in pressure is brilliant because it reduces channeling. As a coffee puck erodes, its resistance decreases, but tapering off the pressure prevents the water from accelerating too quickly and drilling destructive holes in your puck.
Historically, espresso machines only featured occasional analog pressure gauges. To capture precise, high-speed data digitally, the entire machine and group head had to be re-engineered from scratch with custom integrated sensors. This required substantial financial investment to overcome structural limitations, which is why this level of metrics hasn't typically been seen on traditional machines.
Measuring temperature directly inside an espresso slurry is difficult because the system operates under a massive 148 pounds of pressure per square inch, which would cause standard probes to leak or burst. To solve this, the DE1 features a specialized group head with a bore hole that positions a temperature sensor roughly one millimeter above the coffee puck, sitting safely right behind the water screen. This measures the direct interaction effects of the hot water and the coffee without disrupting the shot itself.
Flow tracking is traditionally done using a tiny internal windmill called an impeller. However, standard flow meters fail with espresso because the water flow rate changes drastically and instantly—such as when a sudden channel forms in the puck. Volumetric machines usually just count raw mechanical ticks internally without translating them into a true flow rate because impeller movements at low speeds are highly unreliable.
To accurately trace flow when the water moves too slowly for a mechanical impeller, Decent spent a significant amount of money to map out the entire physical profile of the machine. They created a dedicated physics engine that uses physical dimensions and calculations to step in and accurately estimate the exact flow rate whenever the mechanical flow meter slows down.