The three heating concepts at a glance
Anyone shopping for an espresso machine quickly runs into three concepts: thermoblock, single boiler and dual boiler. Each has its place — but for most home baristas the choice is clearer than it seems.
Single boiler
A classic boiler stores hot water (0.3–1 litre). Upside: stable temperature. Downside: if you want to steam milk right after brewing, you wait 3 to 5 minutes for the boiler to reach steam temperature.
Dual boiler
Two separate circuits: brew water at ~93 °C, steam at ~130 °C. Brew and steam at the same time, excellent temperature stability. Downside: expensive. Good dual boilers cost €1,500–3,500.
Dual-circuit thermoblock
Water passes through a metal block with a heating coil — at temperature in seconds. The modern dual-circuit thermoblock has two independent heating circuits, which solves the simultaneity problem of older thermoblock machines.
What actually matters more than the machine
Surprising for many: the grinder has more influence on the espresso than the machine. A €300 machine with a €200 grinder beats a €500 machine with a cheap grinder every time.
- Grinder with 55–64 mm burrs: €150–350
- Consistent particle size → even extraction
- Adjustability matters more than wattage