← All terms
Steam boiler
The larger boiler that produces steam for milk texturing and hot water for tea — typically held at 120–130 °C and 1.0–1.5 bar.
Category: Boilers & Heating
A pressurised boiler held at steam temperature (around 121–125 °C, depending on pressure) and partially filled with water. The space above the water fills with steam, which is released through the wand on demand.
Why it matters — Steam boiler size and pressure determine how powerfully and how continuously the machine can steam milk. Larger boilers (1 L+) sustain steam through several back-to-back drinks; smaller boilers run out of pressure and need recovery time.
Good to know
- Most prosumer machines run a 1.0–1.5 bar steam boiler; commercial machines run 1.0–2.0 bar.
- Higher boiler pressure means more steam power but also more aggressive steaming — too much pressure can blow milk apart instead of texturing it.