Semi-Automatic Buying Guide

The big choice. There’s a multitude of features and finishing touches to any given machine, but to choose a machine you have decide what you need it to do. For example, are you just going to brew espresso a couple times a day, or maybe make 4 cappuccinos when the guests show up for cards? Once you have your needs sorted, you’ll need to ask yourself what your budget is. So you will have to think about capacity, speed, and features. The simplest way to approach deciding which machine to purchase is to first consider whether you want a single boiler, heat exchanger or a dual boiler machine.

  • How will you be preparing your coffee?
  • Does it offer a suitable range of adjustments so you can dial in your brew properly and make changes from one coffee to another coffee?
  • Are the grinds it produces uniform in shape and size?

Below are the features that answer these questions. Defining features to consider are blade grinders vs burr grinders, stepped vs. stepless, and doser vs. doserless.

Price Range & Considerations


When considering a semi-automatic machine, you want a capable piece of equipment that can brew great coffee for you and a guest without much commitment to the craft. Semi-automatic machines tend to be smaller, with lower capacities when compared to larger equipment. Some skill is required, but there are tricks of the trade like pressurized portafilters to help brew with consistent quality. Maintenance can be simple, but it’s more hands on than a super-automatic.

Semi-automatics tend to be toward the lower end of the price range, but you will likely need to consider a grinder as well to complement your machine.

Single Boiler Dual-Use


Single Boiler Dual-Use espresso machines are the most basic semi-automatic models. These machines have a single boiler that is used for both brewing espresso and steaming milk. The small size and low cost provide an easy entry into home brewing. There are also higher end machines with single boilers that are equipped with PID temperature controllers. These machines are often purchased by people who are more interested in precise control over the temperature of their and may not be concerned about milk steaming.

Benefits

Compact:

Single-boiler machines tend to be much smaller when compared to the bulky, semi-commercial machines that populate the middle to high end range of semi-automatics. Their narrow profiles make them great fits for apartments or smaller kitchens where space is more of a concern than perfect espresso.

Rapid Heating:

With much smaller boilers to heat, these machines reach brew temperature much more quickly when first turned on (5-15 minutes).

Easy to Use:

Designed for less discerning consumers, the pressurized portafilters and auto-frothing wands make these kinds of machines much easier to use in most cases than high end models. Machines like the Gaggia Classic have both the pressurized filter basket for easy use and a commercial basket for producing a real commercial style espresso.

Less Expensive:

While a high end single-boiler machine can still run many hundreds (and over $1000) of dollars, in most cases these machines are considerably cheaper than their prosumer counterparts.

Heat Exchanger


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.

Benefits

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.

High Capacity:

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.

Temperature Stability:

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 stainless steel housing and body parts, polished metals frame, curved edges, raised legs, and visible pressure gauges.

Dual-Boiler


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.

Benefits

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. PIDs help to ensure temperature stability while brewing as well as the ability to make fine adjustments to brew temperature to better suit specific coffees. In Dual Boiler machines, because each boiler is maintained at a unique temperature, a PID is much more practical.

Temperature Stability:

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. With two boilers, you can have a dedicated heating element and temperature controller for both your brew water and steam.

With dedicated heating elements for brewing and steaming, E61 style groups, and a PID controller, Dual Boiler machines are best suited to guarantee that your espresso is brewed and served at the preferred temperature.

Common Features


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 (thermal syphon) 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 Pump:

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 noisier when operating. These pumps take a few seconds before ramping up to full pressure when first switched on, which some users may prefer for pre-infusion.

Rotary Pump:

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 and allow owners to more easily adjust brew pressure. The rotary pumps in these machine are the same ones used in large commercial machines.

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 with rotary pumps but you will find it a few vibration pump machines like the Expobar Office Lever and Brewtus.

No-Burn Wand:

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.