Which espresso machine is right for me?

The espresso machine that meets your needs is the best fit for you. This sounds trivial, but it's actually decisive 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.

Are cappuccino and latte macchiato high on your list? Then a dual boiler espresso machine quickly makes sense.

Those seeking the highest consistency and performance will be happy with a dualboiler espresso machine.

In this article, we work out the differences between the various espresso machine systems: single boiler, dual boiler, and dualboiler. By examining the strengths and weaknesses of these machines, it quickly becomes clear which espresso machine suits you and is therefore the right choice.

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

If you previously had a capsule machine and are now switching to a portafilter for the first time, our beginner's guide for capsule switchers provides a good foundation: What changes? What does getting started really cost? And which coffee is right to start with?

How the single boiler espresso machine works

A single water circuit runs through the single boiler espresso machine via a single boiler. The boiler's job is to heat the water to the required temperature. For brewing espresso, 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 steam, the boiler temperature is heated to 120 – 130 degrees. With the single boiler, this must be done with the same boiler that heats the brewing water.

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

Before further espresso shots, the boiler temperature must first be brought back down to the brewing temperature of 92 – 96 °C degrees. We explained this principle in detail using the example of the Rancilio Silvia.

Illustration of single boiler espresso machine

Temperature surfing is essential for delicious coffee

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

If you can't reach sufficiently high temperatures with the steam pressure, you won't be happy steaming. At low boiler temperatures, large amounts of water instead of steam are blown into the milk. This makes it impossible to steam the milk and it becomes increasingly diluted with water.

With single boilers, it's absolutely necessary to become familiar with your espresso machine so you can estimate the timing between heating and cooling.

Does the single boiler make good espresso?

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

Pros: What speaks for the single boiler

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

Cons: What speaks against the single boiler

• It's not automatic. It requires a certain engagement with the machine to master it.
• Temperature management required to achieve good beverage results.
• While you can learn to operate the machine, since there's already a lot to learn for "espresso beginners," 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, lack of temperature consistency.

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

Pro tip: If you like to tinker, you can retrofit many single boilers with PID control. This promises high temperature stability and turns the single boiler into a machine with high precision – unbeatable in terms of value for money. We'll explain how this works in a later article.

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 spiral-shaped tube is threaded through an aluminum block. A heating element runs along the tube. The water is heated as it flows through the tube. The process corresponds to a flow-through 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 relatively quickly through a few shots without coffee loaded.

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

It becomes problematic when many or few espressos are brewed. When pulling many espressos or long drinks (lungo, café crème-style) in succession, the surroundings cool down due to large amounts of cold water flowing through, and the water no longer heats to a sufficient brewing temperature.

If the water flow is slow, for example due to very finely ground coffee powder, the water heats above the target temperature.

The larger the thermoblock, the better

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

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 with higher or lower flow rates.

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

Pros: What speaks for thermoblock espresso machines

• Quick heat-up
• Depending on installation and tuning, with precise temperature and correspondingly good espresso
• Hardly any 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

Suitable for: Bargain hunters willing to compromise on quality

How the dual boiler espresso machine works

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

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

Illustration of dual boiler espresso machine

With the dual boiler system, milk steaming is a joy

Dual boiler espresso machines are the darling of all cappuccino drinkers. The hot boiler produces vigorous steam, which allows you to steam milk and pull espresso simultaneously. This is really a huge difference from the single boiler espresso machine, where you have time to meditate between brewing espresso and steaming milk. Temperature surfing is a thing of the past compared to the single boiler.

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

Dual boiler and temperature consistency

If you compare the temperature fluctuations of the dual boiler with those of the single boiler espresso machine, the difference is striking. But the dual boiler also has its "quirks." The brewing water is heated by the retention time in the heat-exchanging tube. If you don't brew espresso for a longer period, the temperature of the brewing water equals the ambient temperature. In other words, it's more than boiling hot. That's why flushing – running the group head without coffee – is very important with heat exchangers. This removes the heated water from the tube and the incoming water is already at temperature.

If you brew one espresso after another at a family festival, there's a risk that the brewing temperature falls below the 90 °C threshold. This leads to sour-tasting espressos and reduced extraction capability.

Pros: What speaks for dual boiler espresso machines

• Espresso and steaming capability both good
• Simultaneous steaming and brewing is possible (large boiler)
• Good temperature consistency

Cons: What speaks against dual boiler espresso machines

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

Suitable for: Espresso lovers and cappuccino drinkers.

Options for dual boiler espresso machines

Espresso machines with a dual boiler system are available in many variants from numerous dealers. Of course, these machines each have certain advantages and disadvantages and different construction features, such as slightly larger or smaller boilers and different aesthetics.

Two improvements to the dual boiler 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 a good explanation of how this works here. PID stands for Proportional Integral Differential.

PID control helps ensure that the espresso machine heats precisely in its target range. The target range can be adjusted with a controller, though with dual boilers it's important to note that you're always changing the boiler temperature, which affects both the brewing temperature and the steam pressure. If the steam pressure is insufficient, the boiler temperature can be increased. However, this also increases the temperature heating the heat exchanger, making longer flushes or purges advisable.

Rotary pump vs. vibration pump

Another upgrade for the dual boiler is a rotary pump. The rotary pump is more powerful and heavier. The rotary pump is quieter than the vibration pump, which can be beneficial 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 boiler 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 boiler models, check out our comparison of 12 dual boiler espresso machines.

Dualboiler espresso machine – function and use

No question, anyone investing in a dualboiler is buying temperature precision that shows with every espresso preparation. Two separate boilers provide the temperature that's needed. The steam boiler brews at the desired 120 – 130 °C and the brew boiler delivers precisely the set brewing temperature between 90 and 96 °C.

The juggling act with temperatures comes to an end. The usually larger steam boiler is controlled by a pressure switch to the appropriate pressure. In the brew boiler, PID control manages the brewing temperature with precision to a tenth of a degree.

Many dualboilers also come standard with a rotary pump, which contributes to the machine's durability in terms of power and robustness. Consistency and precision in brewing – that's what defines dualboiler systems. Even with higher beverage frequency, these machines rarely struggle.

Illustration of dualboiler espresso machine

Consistency from shot to shot and during extraction

Espresso quality from shot to shot is shown above all through reliability in the system. The decisive factors here are temperature and pressure at each shot and within each brewing. Consistency during the brewing time is a factor we haven't explored much with the other machine types.

There, the challenge already existed in beginning the brewing with the same brewing temperature. Within a shot, temperature often fluctuates as well. This is because, for example, colder water flows through the heat exchanger, which encounters less resistance in the coffee bed during the second part of an espresso shot than in the first part of the brewing.

The dualboiler masters consistency here because it's supplied from a perfectly tempered water reservoir.

Steaming milk until the stadium is full

Even if the Kelly Family is visiting, the milk foam flows. And the best part: should we overdo it and empty the steam boiler to exhaustion, the espresso isn't affected. This is the advantage of the independent boiler for both purposes.

Steam pressure can be increased by raising the temperature in the steam boiler, thus also increasing the steaming speed. If you prefer to steam more slowly, you can reduce the pressure somewhat. The brewing temperature is not affected here either.

Semi-professional use

A single-group dualboiler is suitable for small catering, larger family events, 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 for catering events. What we like about them: unlike commercial machines, these machines built for household or office use run on standard household current of 220/230 volts. Depending on the location, this is a major advantage.

Of course, there are also large qualitative differences between dualboilers, which we'll explore further in our tests of individual machines. For machines in the quality class of La Marzocco GS 3, we can say that they also look good as a starter for a small café. Should business pick up, you can add another machine of the same type, and you already have a two-group setup. If business is slower, one of the two machines can already be cleaned and "put away" (café jargon).

Turn off the steam boiler and save energy

Sensibly, the steam boiler can be manually deactivated. This makes sense when only espresso drinkers are present. This way you save energy and protect both climate and wallet. For us, this is a decisive quality criterion for a dualboiler.

The size of the brew boiler is repeatedly the subject of discussion. If it's too large, the brew water sits unnecessarily long in the boiler and is repeatedly heated and only slowly replaced. Also, a larger boiler takes longer to reach temperature. A larger boiler particularly makes sense if, for example, half the office wants an espresso during lunch break.

Pros: What speaks for dualboiler 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 dualboiler espresso machines

• High price
• Dualboiler doesn't always mean PID and rotary pump. Be sure to check carefully what else is built into the machine.

Examples of dualboiler espresso machines

Profitec Pro 300 Dualboiler, 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 various types of espresso machines. However, the note about a quality grinder should still be placed here at the margins. As a Kaffeemacher, we observe both in commercial establishments and in private households time and again that the choice of Kaffeemacher grinder is not sufficiently considered. We've already seen absurd combinations like a 7000 CHF/6500 € espresso machine with a Kaffeemacher grinder for 360 CHF/290 € next to it.

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 1/4, 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?

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