Espresso of a boiler

A boiler machine heats the water in a metal tank that serves two things: making coffee and producing steam. But not at the same time: to vaporize milk, the boiler has to rise from temperature, and then let it cool before the next coffee. The Silvia Rancilio is the classic example.

If you take more than anything espresso, or a drink with milk from time to time, it goes great. With PID temperature control, stability improves a lot.

• In favor: solid construction, standard parts and long life.
• In favor: good temperature for coffee, especially with PID.
• Against: you can't make coffee and steam at once.
• Against: uncomfortable to prepare several drinks with milk in a row.

It costs €400-900. Look for 58 mm filter holder, a PID or at least a reliable thermostat and a steam spear with good power. Appreciates that there are spare parts and technical service nearby.

Cheapest alternative: a thermoblock machine (€150-600).