Ask a barista what makes a great espresso and you might hear about the beans, the grind, or the roast. Ask an engineer and you'll get a different answer: it's the choreography. A great shot isn't one event — it's five stages, each doing a different job, in a sequence that lasts about half a minute. Get the sequence right and everything else gets easier. Get it wrong and no grinder can save you.
Most portable machines treat pressure like a light switch: off, then full blast. Café-grade extraction treats it like a curve — rising, holding, and easing off on purpose. That's the idea behind the five-stage extraction curve the PURA NEO Pro runs on battery power, managed by Brew OS. Here's what each stage is actually doing to your coffee.
Stage 1 — Heat: everything starts at 92°C
Before pressure matters, temperature sets the table. The NEO Pro's 120W boiler brings its 70ml tank up to 92°C — the window where the desirable compounds (sweetness, aromatics, body) dissolve readily without dragging harsh bitterness along.
Temperature is the quietest variable and the most punishing to get wrong. Too cool, and the shot tastes thin and sour no matter how good the beans are. Too hot, and bitterness arrives early and won't leave. This is why the curve starts with heat: every stage that follows assumes the water is exactly where it should be.
Stage 2 — The bloom: a gentle, low-pressure start
Here is where the "Starting Curve" earns its name. Instead of slamming the puck with full pressure, the first stage wets the grounds gently at low pressure, letting water soak through the full 16g bed before real extraction begins.
Why does the gentle start matter so much? Because a dry puck is full of microscopic weak spots. Hit it with full force and water takes the path of least resistance — a phenomenon called channeling — which over-extracts some grounds and under-extracts others in the same shot. The result is the worst of both worlds: sour and bitter at once. A proper bloom saturates the puck evenly, so when pressure rises, the whole bed extracts as one. It's also where sweetness and a stable crema begin.
Stage 3 — The ramp: pressure climbs, the shot wakes up
With the puck saturated, pressure builds toward the full extraction window. This is when the first drops appear and the stream darkens into that syrupy flow. Inside the puck, trapped CO2 escapes and the coffee's oils begin to emulsify — the physical process that gives espresso its body instead of tasting like strong drip coffee.
A controlled ramp matters because it keeps the puck intact while the real work starts. Jumping straight to peak pressure is how channeling happens; climbing into it is how evenness happens.
Stage 4 — Full extraction: the true 6–9 bar window
This is the main event, and it's where honesty about pressure counts. The number that matters is the pressure at the puck — where water meets coffee — and for the NEO Pro that's a true 6–9 bar. That's the range where extraction runs deep enough to build body and crema without bulldozing the puck into channeling.
A word on the numbers you see on boxes: a "20 bar" figure on many machines describes the chamber's structural pressure rating — what the hardware can withstand — not the pressure doing the extraction. The puck never feels that number. Judge a machine by the pressure at the coffee bed, measured honestly, not by the biggest number on the packaging.
Stage 5 — The taper: knowing when to stop
Extraction has a tail, and the tail is bitter. The last compounds to dissolve are the harsh ones, so a well-designed curve eases pressure down at the end instead of squeezing the puck dry. It's the difference between a finish that tastes sweet and clean and one that turns astringent in the last sip.
Think of it like searing: high heat does the work, but you pull the pan off before things burn. The taper is the curve's way of pulling the pan off.
Five stages, one battery, no outlet
Running this sequence used to require a countertop machine with a rotary pump and a trained hand. The NEO Pro runs its five-stage Starting Curve on battery power — heating to 92°C and pulling a true 6–9 bar shot through a 16g/48mm basket, extracting bottom-up for a richer crema — in a 760g body you can fit in a jacket pocket.
The curve does the choreography, but you still set the stage. Three things make any staged curve perform its best:
- Fresh whole beans, ground just before brewing. CO2 is what builds crema; it fades within weeks of roasting. (We sell whole beans only — grind fresh, every time.)
- A fine, even grind. The puck's resistance is what the curve pushes against; an uneven grind gives pressure nowhere consistent to go.
- A ~1:2 ratio. 16g of ground coffee in, about 32g of espresso out — then adjust to taste.
Pressure isn't a number on a spec sheet. It's a sequence — heat, bloom, ramp, extraction, taper — and when all five stages do their jobs, the cup tells you. Your coffee, anywhere.