Espresso Machines: Single Boiler VS Dual Boiler VS Heat Exchange

Deciding on a new espresso machine but paralyzed by the possibilities of different boiler types? Let’s help. 

Choosing an espresso machine often comes down to budget, drink preference, and usability. Machines with internal boiler types such as a Single Boiler, Heat Exchange, and Dual Boiler all have different benefits and draw backs, and understanding the differences is a key process in deciding which espresso machine would be best suited to your liking. 

Single boilers are what we find in most entry-level and consumer espresso machines. They utilize the same boiler for both coffee brewing and milk steaming. As such, they are usually less expensive, however can be frustrating to use for large groups of people or those who primarily drink lattes, cappuccinos, and other milk drinks. Switching between coffee brewing and steaming is a time-consuming process, and often takes minutes for the boiler to cool down after steam usage. 

Dual Boilers have independent boilers for both coffee brewing and milk steaming, allowing the machine to prepare both coffee and milk at their ideal temperatures, and while doing both simultaneously. These machines a fast and excellent performing barista’s dream, however come with the drawback of generally being the most expensive of all boiler types. 

A Heat Exchange machine intelligently exchanges heat from a single steam boiler into a secondary nested boiler used for brewing coffee. As such, they allow simultaneous milk steaming and coffee brewing. These machines are often less expensive than dual boiler alternatives, but are less thermally stable. Temperature consistency tends to change throughout the coffee extraction process which may lead to less predictable extractions. This however has its own benefits which is loved by coffee aficionados, discussed below. 


Single Boiler Espresso Machines 

The classic Single Boiler espresso machine is what you will find in most hobby barista homes. They are generally less expensive and often yield very similar results to more expensive espresso machines. Single boilers need time to switch between coffee brewing and steaming, and so are the slowest in the beverage preparation process of all the machine types. To accommodate this transition, Single Boilers are often made with smaller boilers and are generally cannot make a large number of beverages back-to-back without waiting minutes between. 

That being said, these are the perfect fit for households of only a couple people, and especially for those who mostly enjoy espresso, americanos, or other non-milk based beverages. 

Our Top Single Boiler Machine Recommendations:

  • Lelit Anna 2: Our ‘staff pick’ for best entry level single boiler machine. Inside is a PID temperature controller which makes the coffee quality from this machine almost indiscernible from machines thousands of dollars more expensive. 
  • Gaggia Classic Pro: a classic staple and great first machine choice for any coffee enthusiast. This machine has renowned build quality and parts are readily available, however lacks the PID featured in the Lelit Anna 2.  
  • DeLonghi EC702: At half the price of the other machines, the EC702 poses an excellent choice for budget constrained purchasers. This machine features a high-quality stainless-steel boiler and is a decent introductory machine for those getting started. 


Why Heat Exchange Machines? 

As discussed above, Heat Exchange machines allow for simultaneous coffee brewing and milk steaming due to their unique boiler design. Intrinsic to this is less thermal stability, and the temperature tends to fluctuate during the brewing process. That being said, many coffee aficionados tend to prefer the complexity of coffee from a Heat Exchange machine due to the unique characteristics of the coffee being extracted at slightly different temperatures. The espresso pulled from Heat Exchange machines is often regarded as tasting the most interesting and well-rounded of the three. 

Unfortunately, these machines are still less predictable and many people often prefer the process and consistency of working with Dual Boilers as a result. 

Our Top Heat Exchange Machine Recommendations: 

  • Rocket Appartamento: Small counter-top footprint with style 4x its size! The Appartamento is a modern machine with a traditional aesthetic, excellent build qualitym, and coffee quality to match. 
  • Lelit Mara X: The Mara X features a PID temperature controller, which helps compensate for the lack of thermal stability in the Heat Exchange boiler design, however maintains the unique coffee characteristics found in these machines. 
  • Profitec Pro 500 with Flow Control: The luxurious choice of the bunch, the Pro 500 features a PID temperature control and a unique flow control at the group head for precision control on the extraction process. This machine is a coffee artisan’s dream. 


Dual Boilers - Café performance at Home

Dual boiler espresso machines are a home barista’s dream. These machines provide simultaneous coffee brewing and milk steaming, consistent temperatures, and larger boilers to accommodate back-to-back drinks in quick succession. They are the ideal boiler type to many people and provides the easiest and streamlined performance, if you can afford it. 

Our Top Dual Boiler Machine Recommendations: 

  • Lelit Bianca 2: Arguably the best ‘band-for-buck' dual boiler machines on the market. The Bianca 2 provides many features from machines which are much more expensive, and is often a go-to-choice for people who want the best possible performance for each dollar spent.his also features a rotary pump, which maintains excellent pressure in near-silent operation.   
  • Rocket R58: If money is no object, the R58 fits all the bells and whistles you could imagine in a classic design and small countertop footprint. Its traditional aesthetic is accompanied by some of the industry’s best and latest engineering gracefully hidden under its elegant stainless-steel housing.
  • Rancilio Silvia Pro Dual Boiler: A notable mention. The Silvia Pro features a dual boiler, PID temperature control, and the excellent build renowned build quality from the original Rancilio Silvia – all of this at a competitive price point for what it offers.  


Whichever machine you choose, we have plenty of options available. Our customer service team is happy to help with any other questions you may have and can be contacted here.

Thanks for Reading! 

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