Prosumer Buying Guide
The big choice. There’s a multitude of features and finishing touches to any given machine, but the simplest way to approach deciding which machine to purchase is to first consider your needs and the type of boiler in a given machine. You’ll generally find heat exchangers and dual boilers in the Prosumer category.
Price Range & Considerations
When considering a prosumer machine, you’re looking for high volume, high-performance equipment made of the best parts available. Prosumer machines offer all the control over brewing you could need, demanding a certain level of skill and knowledge to get the best performance out of them. Maintenance is more particular and more important for prosumer machines, as well. However, if you want a machine that can pull lots of barista-quality shots without delay, you’ll want a prosumer machine.
Prosumers stand at the more expensive side of the price range, and will need high-end grinders to get their best performance.
These espresso machines are some of the most commonly found machines in the Prosumer category. Designed with boilers that feature heat exchange technology they can brew and steam simultaneously by maintaining a constant supply of both steam and brew water. The basic concept is the brew water is in a small tube that is supplied with fresh water each time you hit the brew button or ever to brew. That tube goes into the boiler and the large mass of boiling water surrounding the tube heats the water as it passes through.
Heat exchange machines are a great choice for developing brewing techniques. They offer better temperature stability, higher capacity, and professional grade components. Learning how to brew at consistent temperatures can be learned but is not what these machines are generally well known for, particularly when compared to a double boiler machine.
Brew and Steam Simultaneously:
Because the boiler is configured to supply both brew water and steam at the same time, Heat Exchange machines allow you to brew espresso and steam milk simultaneously. As a result, total prep time for milk drinks is significantly shortened.
With larger boilers and water reservoirs (or, in some cases, direct water connections), Heat Exchange machines have much higher outputs for both brewing and steaming. Whether you’re entertaining at home, or brewing in a cafe or kiosk you’ll benefit from from having much more water and steam at your disposal and much shorter wait times.
Thanks to larger, higher quality boilers and features like the E61 group, Heat Exchange espresso machines are better suited to maintain proper brewing temperature than most single-boiler machines.
Works of Art:
Owing to their status as both luxury home items and commercial-grade brewing equipment, many machines in the Heat Exchange category have aesthetic considerations that are lacking on less expensive models. Common features include polished metals frame, curved edges, raised legs, and visible pressure gauges.
Dual Boiler espresso machines are built with two boilers instead of one. Each boiler has its own dedicated application (brewing or steaming respectively) and in most cases the steam boiler can be switched off when not needed. Dual Boiler machines feature many of the same benefits and design features present in Heat Exchange models such as high capacity, water line adaptability, rotary pumps, E61 Groups, and the ability to brew and steam simultaneously. They are typically found on the most powerful machines available.
The benefits of a dual-boiler machine are similar if not that same as a heat-exchanger machine, along with the following:
PID Temperature Controller:
Although some heat exchange machines feature PID controllers, they are much more common on Dual Boiler espresso machines. PID stands for Proportional, Integral, Derivative, and the controller’s themselves allow you to monitor and adjust the temperature inside of the boiler. A PID controller continuously calculates an error value as the difference between a desired setpoint and a measured process variable and applies a correction based on proportional, integral, and derivative terms (sometimes denoted P, I, and D respectively) which give their name to the controller type.
PIDs help to ensure temperature stability while brewing as well as the ability to make minor adjustments to brew temperature to better suit specific coffees. PID controllers are less common on Heat Exchange machines because temperature bleed from the boiler and the necessity of the cooling flush make it more difficult to maintain the temperature of the supply of brew water. In Dual Boiler machines, because each boiler is maintained at a unique temperature, a PID is much more practical. To simplify It calculates what temp boiler needs to be maintained to brew at the temperature you set to brew at, It also factors that in an offset fashion it will factor in the known heat loss from boiler to group head.
The concept of temperature stability is important for all varieties of espresso machines, but Dual Boiler machines are best suited to maintain stable temperatures while allowing a user to brew and steam at the same time. When brewing espresso, you want the temperature of the espresso in your cup to be as close to the temperature in your boiler as possible. With two boilers, you can have a dedicated heating element for your brew water like in a single-boiler machine, while still having a supply of steam so you can brew and steam at the same time.
With dedicated heating elements for brewing and steaming, no temperature bleed, E61 style groups, and a PID controller, Dual Boiler machines are best suited to guarantee that your espresso is brewed and served at the correct temperature.
E61 Group/Brew Group/Group Head:
The E61 group is one of the most commonly used group head designs on prosumer espresso machines. The group is constantly heated by a supply of water from the boiler in order to maintain high temperatures while brewing and protect against the loss of heat at the group. Alternative heating solutions included electric heating elements as well as passive heating from the brew boiler.
Vibration pumps are common on a wide range of espresso machines and operate by using a piston to push water through your machine. These kinds of pumps are less expensive than rotary pumps, and machines that use them will in turn be less expensive as well. More often than not, a machine using a vibration pump will use a water reservoir as opposed to an inline water connection. Compared to rotary pumps, vibration pumps tend to be much noisier when refilling the boiler after brewing, and tend to be less susceptible to scale buildup over time. These pumps take a few seconds before ramping up to full pressure when first switched on.
The main alternative to vibration pumps, rotary pumps are a more expensive alternative that are common among some of the most expensive home machines on the market. In many cases, these pumps will be found on hybrid reservoir/plumbable machines, or on machines that have no built in reservoir at all. These pumps are quieter in general than vibration pumps when it comes to refilling the boiler, and allow owners to more easily adjust brew pressure.
Plumbable/Water Line Adaptable:
Certain machines allow you to plumb them directly into a water line rather than using the reservoir. This feature is more common on machines designed for commercial applications (Nuova Simonelli) and on machines with rotary pumps.
Some steam wands, known as “no-burn” wands are insulated to keep the surface from getting hot too quickly and protecting people from burning themselves by touching it. Even with insulation however, the wand will heat up eventually after steaming for long enough.
Hot Water Wand:
In addition to steam wands, many prosumer machines also feature wands dedicated to hot water. By opening a valve you can dispense water directly from the boiler which is ideal for hot cocoa, tea, and americanos.