Which espresso machine is right for me?

The espresso machine that meets your needs is the best fit for you. That sounds trivial, but it's actually crucial in determining which espresso machine is right for you.

Are you an espresso purist? Then a single boiler espresso machine might be perfect for you.

Do cappuccino and latte macchiato rank high on your list? Then a dual circuit espresso machine quickly makes sense.

If you're looking for maximum consistency and performance, you'll be happy with a dual boiler espresso machine.

In this article, we'll work out the differences between the various espresso machine systems: single boiler, dual circuit, and dual boiler. Based on the strengths and weaknesses of each machine, you'll quickly see which espresso machine is right for you and the correct choice.

If you want to learn how to prepare espresso step by step, this tutorial with video will help.

How the single boiler espresso machine works

One water circuit runs through a single boiler in the single boiler espresso machine. The boiler's job is to heat the water to the required temperature. For espresso preparation, the ideal temperature depending on the coffee and roast is between 90 and 96 °C.

Temperature is also needed to steam milk. To generate sufficient water vapor, the boiler temperature is heated to 120 – 130 degrees. With the single boiler, this has to happen with the same boiler that heats the brewing water.

After brewing an espresso with a single boiler system, the heating is increased. This can be started manually at the push of a button. The small, usually powerful boiler then heats up from the brewing temperature to approximately 125 °C. When the target temperature is reached, you can begin steaming.

Before pulling more espressos, the boiler temperature must first cool back down to the brewing temperature of 92 – 96 °C degrees. We've explained this principle in detail using the Rancilio Silvia as an example.

Darstellung Single boiler espresso machine

Temperature surfing is essential for delicious coffee

Mastering the temperatures is the key to good coffee on a single boiler espresso machine. Brewing temperatures that are too high, over 100 °C degrees, lead to very unpleasant coffee taste. The coffee becomes very bitter and sour – both at an intensity level you won't want to drink.

If you don't reach sufficiently high temperatures with the steam pressure, you won't be happy steaming. At low boiler temperatures, large amounts of water, rather than water vapor, are blown into the milk. This makes it impossible to steam the milk and simultaneously dilutes it more and more with water.

With single boilers, it's absolutely essential to get to know your own espresso machine well so you can estimate the heating and cooling times.

Does the single boiler make good espresso?

Absolutely! The espresso tastes just as good on a single boiler espresso machine as espresso from a small car-priced commercial espresso machine. The prerequisite is that the temperature is right. And in the single boiler price range, this usually can't be read from the outside. You have to learn to master the temperature. Or you can skip the milk steaming function. Then the boiler doesn't have to work for both brewing and steaming and is often better calibrated for the target brewing temperature.

Pros: What speaks in favor of the single boiler

• Makes very good espresso when temperature is correct
• Affordable machines on the market
• Relatively small models also available
• Can be heated up for milk steaming depending on the model
• Due to small boiler, can heat up and cool down relatively quickly

Cons: What speaks against the single boiler

• Not automatic. It requires a certain amount of engagement with the machine to master it.
• Temperature management required to achieve good drink results.
• While you can learn to operate the machine, since espresso beginners have so much to learn anyway, such as properly adjusting the grinder and steaming milk, this machine type is in our view not the perfect starter machine.
• Due to the small boiler, lacking temperature consistency.

Who is the single boiler suitable for? For espresso drinkers and milk steamers with nerves of steel

Pro tip: If you enjoy tinkering, you can retrofit many single boilers with PID control. This promises high temperature stability and transforms the single boiler into a machine with high precision – unbeatable in terms of value for money. We'll explain how this works in a future post.

Examples of single boiler espresso machines

Lelit Victoria PL91T, Gaggia New Classic, Bezzera Hobby, Lelit Grace PL81T, Lelit Anna PL41 LEM, ECM Classica PID, Bezzera Unica PID, Quick Mill Carola, Rancilio Silvia

How the thermoblock espresso machine works

The thermoblock is an alternative to the boiler principle. Instead of a heated water reservoir, a spirally shaped tube is pulled through an aluminum block. A heating element runs along the tube. The water is heated by the tube. The process corresponds to a flow heater.

The major advantage over boiler espresso machines is the relatively short heat-up time. The heating element heats up quickly. The "block" can be brought to temperature quickly through several shots without inserted coffee.

The temperature stability of the thermoblock depends on how the tube is installed, its length, the water flow rate, and the heating power. With well-tuned machines, this is relatively or even very precise during standard operation. Positive examples are machines from Ascaso or the Decent espresso machine.

It becomes problematic when a lot or little coffee is brewed. When pulling many espressos or long drinks (lungo, Café crème-like), the surroundings cool down from the large amount of cold water flowing through, and the water no longer heats to a sufficient brewing temperature.

If the water flow is slow, for example from very finely ground coffee powder, the water heats up beyond the target.

The larger the thermoblock, the better

With most smaller thermoblock espresso machines, the thermoblock is relatively small. To reach the desired target temperature during the short flow time, the block therefore has to be heated significantly higher than the actual target temperature. This further intensifies the problem described above.

The larger the thermoblock, the closer the block's temperature is to the actual target temperature and can thus more consistently deliver the desired temperature even at higher or lower output.

Thermoblock machines are generally not well suited for steaming milk. The pressure built up is relatively low. Additionally, the foam produced has relatively high residual moisture, which dilutes the milk significantly. The pump sprays small amounts of water into the thermoblock to build pressure, which then evaporates and generates pressure. Due to these pulses, the steam also exits the steam wand in pulses, making homogeneous steaming difficult. There are positive counterexamples here too, like the Sage Bambino Plus.

Pros: What speaks in favor of thermoblock espresso machines

• Quick heat-up
• Depending on installation and calibration, precise temperature and correspondingly good espresso
• Minimal limescale buildup
• Relatively affordable

Cons: What speaks against thermoblock espresso machines

• Temperature fluctuations depending on flow rate and water volume
• Dependent on the size of the thermoblock
• Not well suited for steaming milk

Examples of thermoblock espresso machines

Sage Barista Express, Sage Barista Pro, Lelit Glenda PL41, Quick Mill Peagso, ECM Casa V, Lelit Kate PL82T, Ascaso Steel Duo PID, Ascaso Dream PID, Sage Bambino Plus

Who it's suitable for: Budget-conscious with willingness to compromise on quality

How the dual circuit espresso machine works

Two water circuits after the pump characterize the dual circuit espresso machine system. A boiler is the central element. It is heated to a temperature of 120 – 130 °C. The steam pressure for milk steaming is drawn directly from this boiler. Additionally, a tube runs through the boiler that transports the brewing water toward the espresso preparation.

The tube functions as a heat exchanger. As it flows through the tube surrounded by hot water, the fresh water heats up. The hot water in the boiler corresponds here, in a sense, to the thermoblock.

The wall thickness of the tube and the "residence time" of the brewing water through the boiler are crucial in determining how much the brewing water heats up.

Darstellung Dual circuit espresso machine

With the dual circuit system, steaming milk becomes a pleasure

Dual circuit espresso machines are the favorites of all cappuccino drinkers. The hot boiler generates powerful steam, allowing you to steam milk and pull espresso at the same time. That's really a huge difference from the single boiler espresso machine, where you have time to meditate between brewing espresso and steaming milk. Temperature surfing becomes a thing of the past compared to the single boiler.

The dual circuit also has enough power to brew several espressos in a row. Depending on the boiler size, you'll notice a slight performance drop after 2 to 6 steamed milk pitchers. But it's quickly overcome if you give the machine time to heat up again.

Dual circuit and temperature consistency

If you compare the temperature fluctuations of the dual circuit with those of the single boiler espresso machine, the difference is striking. But the dual circuit also has its "quirks." The brewing water is heated by the residence time in the heat-exchanging tube. If you don't brew espresso for a long time, the temperature of the brewing water corresponds to the ambient temperature. In other words, it's more than boiling hot. That's why flushing, i.e., a blank shot, is very important with heat exchangers. This removes the heated water from the tube, and the incoming water is already at temperature.

If you're pulling one espresso after another at a family party, there's a risk that the brewing temperature will drop below the 90 °C threshold. This results in sour-tasting espressos and reduced extraction capability.

Pros: What speaks in favor of dual circuit espresso machines

• Good espresso and steaming capability
• Simultaneous steaming and brewing is possible (large boiler)
• Good temperature consistency

Cons: What speaks against dual circuit espresso machines

• Home-use machines are not suitable for large parties or commercial use. Neither the steam pressure nor the brewing water temperature can handle it.
• More expensive than single boiler and thermoblock

Who it's suitable for: Espresso lovers and cappuccino drinkers.

Options for dual circuit espresso machines

Espresso machines with dual circuit systems are available in many variants from numerous retailers. Of course, the machines each have certain advantages and disadvantages and different installations, such as slightly larger or smaller boilers and different aesthetics.

Two improvements to the dual circuit are particularly noteworthy and change both the quality and the price.

PID control

The PID control option regulates the brewing water temperature. You can read how exactly this works gut explained here. PID stands for Proportional Integral Differential.

PID control helps the espresso machine heat precisely within its target range. The target range can be adjusted with a controller, though with dual circuits it should be noted that you're always changing the boiler temperature, which affects both the brewing temperature and the steam pressure. If the steam pressure isn't sufficient, the boiler temperature can be increased. However, this also raises the temperature that heats the heat exchanger, making longer blank shots or flushing advisable.

Rotary pump vs. vibratory pump

Another upgrade for the dual circuit is a rotary pump. The rotary pump is more powerful and heavier. The rotary pump is quieter than the vibratory pump, which is useful depending on where the espresso machine is located.

Due to their robustness and power, rotary pumps are standard in multi-group commercial machines.

Examples of dual circuit espresso machines

Bezzera BZ10, Quickmill Rubino 0981, Bezzera Magica SMN, Bezzera Strega R AL, Profitec Pro 500, ECM Mechanika V, Elba 1 and 2, Rocket Appartamento, Lelit Mara X, Rocket Cronometro Mozzafiatto, Sanremo Cube

To get a really good overview of the most important dual circuit models, take a look at our comparison of 12 dual circuit espresso machines.

Dual boiler espresso machine – Function and application

No question, if you invest in a dual boiler, you're buying temperature precision that shows with every espresso preparation. Two separate boilers provide the temperature that's needed. The steam boiler steams at the desired 120 – 130 °C and the brewing boiler delivers the precisely set brewing temperature between 90 and 96 °C.

The juggling with temperatures comes to an end. The usually larger steam boiler is controlled via a pressure switch to the appropriate pressure. In the brewing boiler, PID control monitors the temperature for brewing down to a tenth of a degree.

Many dual boilers also have a rotary pump as standard, which contributes to durability in terms of power and robustness. Durability and consistency in brewing is what characterizes dual boiler systems. Even with higher drink frequency, these devices rarely falter.

Illustration of dual boiler espresso machine

Consistency from shot to shot and during extraction

The quality of espresso from shot to shot is primarily shown through system reliability. The decisive factors are temperature and pressure with each shot and within a brewing. The consistency during brewing time is a factor we haven't delved deeper into with the other machine types.

There, the challenge was already in beginning the brew with the same brewing temperature. Within a shot, the temperature often fluctuates as well. This is because, for example, cooler water flows through the heat exchanger, which encounters less back pressure in the coffee puck in the second part of an espresso shot than in the first part of the brew.

The dual boiler masters consistency here because it's fed from a perfectly tempered water reservoir.

Steaming milk until the stadium is served

Even if the Kelly Family are visiting, the milk foam flows. And the best part: even if we get carried away and empty the steam boiler to exhaustion, the espresso is unaffected. That's the advantage of independent boilers for both functions.

The steam pressure can be increased by raising the temperature in the steam boiler, thus increasing the steaming speed. If you prefer to steam more slowly, you can lower the pressure a bit. Even here, the brewing temperature is not affected.

Semi-professional use

A single-group dual boiler is suitable for small catering, larger family parties, and depending on the type, for continuous operation. Many machines of this type can also be connected to mains water, which is another advantage.

We regularly use both our La Marzocco Linea, a Dalla Corte Mini, and of course a La Marzocco GS 3 at catering events. What we like about them: unlike commercial machines, those built for household or office use run on standard household power of 220/230 volts. Depending on where they're used, that's a major advantage.

Of course, there are large qualitative differences between dual boilers, which we'll address in more detail in our tests of individual machines. For machines in the La Marzocco GS 3 quality class, however, we can say that these look good starting a small café. If the business takes off, another machine of the same type can be added, and you already have a two-group setup. If things are slower, one of the two machines can already be cleaned and "put away" (restaurant jargon).

Turn off the steam boiler and save energy

Sensibly, the steam boiler can be manually deactivated. This is useful when only espresso drinkers are present. This saves energy and helps the climate and your wallet. For us, this is a crucial quality criterion for a dual boiler.

The size of the brewing boiler is repeatedly the basis for discussions. If it's too large, the brewing water unnecessarily sits in the boiler for a long time and is repeatedly reheated and only slowly replaced. Also, a larger boiler takes longer to reach temperature. A larger boiler mainly makes sense if, for example, at the office during lunch break, half the floor wants an espresso.

Pros: What speaks in favor of dual boiler espresso machines

• Precise brewing temperature
• Brewing temperature and steam pressure independent of each other
• Consistency from shot to shot
• Consistency within a shot
• Suitable for semi-professional use (larger guest volume)
• Some models with commercial components are extremely robust and precise

Cons: What speaks against dual boiler espresso machines

• High price
• Dual boiler doesn't always mean PID and rotary pump. Be sure to check carefully what else is installed in the machine.

Examples of dual boiler espresso machines

Profitec Pro 300 Duablboiler, La Spaziale Dream, Bezzera Duo Top MN, Quick Mill New Vetrano 2B, Rocket R58/Cinquantotto, Bezzera Matrix, ECM Synchonika Dualboiler, Dalla Corte Mini, La Marzocco GS/3, La Marzocco Linea Mini

Espresso grinder as a basic requirement

This article deals with the different types of espresso machines. However, a note about a quality grinder should still be mentioned in passing. As a coffee maker, we observe both in restaurants and in private households that the choice of coffee grinder is often not given sufficient thought. We've already seen absurd pairings like an espresso machine for 7000 CHF/6500 € and next to it an espresso grinder for 360 CHF/290 €.

That's just a shame. The grinder severely limits the quality of the espresso machine in such a setup. When planning a budget for purchasing an espresso machine, we recommend reserving at least ¼, preferably 1/3, of the budget for the grinder. Unevenly ground coffee extracts inhomogeneously and ensures that the quality of your espresso is limited.

Conclusion – Which espresso machine is right for you?

Related topics:

• Cleaning your espresso machine
• My grind size is not your grind size