Two boilers vs heat exchanger in a coffee machine


Alever coffee machine works in a specific way toextract coffee in a portafilter with hot water under a certain pressure. The pressure in the coffee machine is achieved by using a vibrating or rotary pump. Two of the most popular systems for heating the water in an espresso machine is the use of two boilers or a boiler with a heat exchanger.

The performance of the espresso machine is usually determined by the power of the heating element and also the capacity, that is, the volume of hot water and steam that the machine is able to deliver. A higher capacity coffee machine therefore means the ability to make more coffees in a row and also faster steam nozzle function.

When extracting espresso, it's important to control not only thecoffee being roasted but also the water - its composition (which water filtration systems can help you adjust ) and temperature. Precise control and stability of the water temperature gives the barista the chance to achieve the best extractions. And repeatedly. So what will ensure a precise and stable water temperature in the coffee machine?


One of the heat systems used in coffee machines is the boiler with heat exchanger. For example , theNuova Simonelli Musica coffee machine has one built into it . How does it work in practice? Inside the coffee machine there isone large two-litre boiler for heating the water. Inside the boiler, a heat exchanger passes through the boiler, from which the water travels to the head of the coffee machine.

The large boiler in the coffee machine also means there is more than enough steam to make your favourite milky coffee drinks. So with the NS Musica, you can make latte after latte for your whole family. You simply won't run out of water and steam. From a capacity point of view, the power requirement would therefore be met. And what about maintaining temperature stability?

Theheat exchanger ensures a water supply at a temperature suitable for espresso. Unlike coffee machines with a single boiler but without a temperature exchanger, you don't have to adjust the heating according to the stage of preparation. That is to say, whether you are preparing coffee or milk and thus switch between the boiler functions. Therefore, the temperature stability of coffee machines with an exchanger is more precise.

However, it is still within a certain temperature range that can change with each coffee. And thus each espresso may varyslightly, as this method of heating water cannot target a specific water temperature and accurately maintain it with each subsequent espresso.


In contrast to this system ,coffee machines with two separate boilerswork well . Again, I have a demonstration of such a coffee machine from our range. TheLelit Bianca precision coffee machine . This coffee machine has not one, but two boilers with different functions under the hood.

The slightly larger boiler takes care of the hot water in the dispenser and, above all, the steam for the steam nozzle for whipping the milk. The second - smaller boiler has the task of heating the water for the espresso. A thermostat and a separate boiler make the Lelit Bianca a coffee machine capable of keeping the water for making coffee at a constant temperature. This allows you to brew your coffee at the most appropriate temperature, as even a small shift on the thermometer can make a big difference to the coffee's taste.

A dual boiler coffee maker is usually the more expensive piece. It also lacks in compactness, which is something that can't quite be said of the Bianca, as it retains a compact size even with two boilers inside. Even with a slightly smaller steam boiler, it is capable of making a couple of cappuccinos in a row. The biggest advantage is the professional level coffee preparation and the ability to experiment with unique "single origin" coffees.


Both of these types of coffee machine meet the demands of aquality espresso machine. And the decision is then more about whether totake advantage of the possibility of precisely defining extraction parameters such as water temperature. Or whether you're choosing a capable machine for a household full of coffee drinkers where precision trumps practicality.

But both of the coffee makers you've selected are high-performance home coffee makers for making really good coffee that come from the masters - the workshops that make professional lever coffee makers