The Journal
Long-form technical writing on portable espresso. Every article states what is measured, what is calculated, and what is a general explanation.
Portable coffee maker: 9 bar, no electricity
What a portable machine has to do to make real espresso, how it feels to use in two minutes, and where it earns a place at home.
Read → Explainer · Pneumatic technologyWhat is a pneumatic coffee machine?
A working definition, the three devices it is confused with, and the gas arithmetic that decides cost per shot.
Read → Tutorial · Field techniqueHow to make espresso while camping
Wind, cold, altitude and no sink: a nine-minute procedure that produces a repeatable shot outdoors.
Read → Buying guide · EquipmentPortable coffee maker buying guide
Five questions that eliminate most of the market, plus the six red flags hidden in product listings.
Read → Reference · EngineeringHow a pneumatic espresso machine works
Regulation from 57 bar to 9, where the heat actually goes, and why pressure is not flow.
Read → Explainer · PneumaticHow does a pneumatic espresso machine work?
Five stages from sealed chamber to spent puck, and why held pressure is not held flow.
Read → Explainer · Gas systemsCO2 powered coffee machines explained
Why the gas must never touch the water, and what one cartridge actually buys.
Read → Science · ExtractionPressure in espresso extraction
Where 9 bar came from, and why the gauge tells you less than the flow does.
Read → Comparison · FormatsPneumatic vs manual espresso machines
The 240 kg force problem, pressure curves, and a decision rule that holds up.
Read → Analysis · OwnershipAdvantages and limitations of pneumatic machines
Both columns, including the three limitations that make people regret the purchase.
Read →What this journal is for
Portable coffee is a category with a lot of confident claims and very little measurement. Our editorial rule is simple: a number is either measured, calculated from stated assumptions, or labelled as a general industry range. If you cannot tell which of the three you are reading, the article has failed.
That means you will see fewer specifications here than on a competitor's page, and you will know which ones are real.
Publishing schedule
Three long-form articles per week, published in topic clusters rather than as isolated posts:
- Portable coffee makers — categories, buying decisions, ownership costs.
- Pneumatic technology — regulation, pressure, gas budgets, machine design.
- Portable espresso technique — field procedures, temperature, dialling in.
- Coffee knowledge — the extraction science that makes the rest make sense.
- Comparisons — head-to-head, with the failure modes included.
Subscribe to receive new technical articles — roughly every two weeks, one email.