Espresso · Gear
Espresso with heat exchanger
A steam boiler with a tube that heats the water from the coffee as it passes. Coffee and milk at the same time, ideal if you make many coffees with milk.
- Indicative price
- €900–2000
- Capacity
- 1–2 tazas
- Grind
- Fine
The heat exchanger machines, or HX, have a large boiler at steam temperature. The coffee water does not come out of that boiler: it passes through a tube that passes through it and is heated along the way. So you can get a coffee and vaporize milk at the same time.
The trick is in the temperature. If the machine has been standing still for a while, the exchanger water is overheated and the group should be purged for a few seconds before the coffee is prepared. Modern models solve it better, some with PID in the boiler.
- In favor: coffee and steam at once, with a lot of power.
- In favor: robust machines, many with E61 group.
- Against: the coffee temperature is less precise; you have to learn to purge.
- Against: they take time to heat and consume more.
They cost €900-2,000. Search E61 or similar group, manometer, accessible deposit and, if possible, PID. See also the steam power and the boiler size.
Cheapest alternative: a boiler machine (€400-900), agreeing to wait between coffee and milk.
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