When you’re looking for a prosumer-lever espresso machine, you may notice that the type of pump it has is mentioned in the product description.
For example, Rocket espresso machines can use rotary or vibration pumps in their Mozzafiato and Giotto models. So, if you’re considering the Mozzafiato, it is either the Mozzafiato R or V (rotary or vibration).
But what do the pumps do, and how are they different? This article will answer those questions to ensure you know exactly what to expect from the pump of the prosumer machine you choose.
What Is An Espresso Machine Pump?
To ensure water can penetrate and push through the tightly packed fine coffee used for espresso, it needs pressure – a minimum of 9 bars, to be precise. That’s where an espresso machine comes in, as it generates the necessary pressure to push the hot water from the brew chamber to the group head. The water pulsates through the tamped grounds and produces a beautiful espresso in as little as 20 seconds.
Manual espresso makers, like the Flair, use a piston with a long lever to create the necessary pressure. However, most espresso machines nowadays use a small electric pump, which is highly consistent and quickly achieves the pressure needed to make the espresso.
The pump is the heart of an espresso machine. The dominant machines in the market are all pump-driven, which have been around since the 1960s. However, there are two main types of pump machines – vibration and rotary, and they each have advantages and disadvantages, ranging from cost to consistency. There are other key differences between the two, as well. Let’s examine what each offers.
What Is A Vibration Pump In Espresso Machines?
A vibration pump is also called a vibratory pump or vibe pump, and it’s common in domestic espresso machines.
Inside a metal coil is a piston. That piston also contains a magnet attached to a string. An electrical charge goes through the coil, which makes the magnet propel the piston quickly back and forth. When this happens, the pressure pulsates water through the espresso machine at approximately 60 pushes a second.
Pros And Cons
Vibe pumps are smaller than rotary pumps. They’re also cheaper and easier to replace. However, they have disadvantages.
For example, they’re louder than rotary pumps, and they’re not built to be plumbed, meaning they’re restricted to getting water from the reservoir. They also don’t allow you to directly control the pressure, meaning you’ll need a bypass to achieve this.
What Is A Rotary Pump In Espresso Machines?
Most commercial and prosumer espresso machines use a rotary pump, sometimes called a rotary vane pump.
Rotary pumps are complex mechanical devices. A motor is also required to spin a disc offset by a cylindrical chamber. There are also segments in the disc, determined by veins. The veins press against the outer chamber’s walls, reducing the section’s size and generating pressure. While the sections are larger, water enters while it is pushed out as the size reduces.
Pros And Cons
Rotary pumps tend to last longer than vibration pumps. They’re also quieter and provide more consistent pressure. You can also control the pressure by moving the dial with a screwdriver.
One of the biggest drawbacks of rotary pumps is their larger size, thanks to the motor required to power them. They’re also considerably more complex than vibration pumps, making them more expensive. Finally, they’re not as readily available, making them harder to replace. However, they are less likely to break.
Vibration Pumps Vs. Rotary Pumps
The good news is that both pumps produce beautiful espresso, even if people are conflicted about which makes the best. So, some espresso enthusiasts insist that vibration pumps build the pressure more slowly, which creates a preinfusion for a better coffee. Others say that rotary pumps offer more consistency through the brewing process, making a better shot.
Generally, only real experts are likely to tell the difference in coffee between the two, assuming you use the same type of beans and variables in both. Nevertheless, if you were to pull the shots side by side using the two pumps, you’d notice a difference in their appearance. That’s because the shot from a rotary pump machine is generally steady, while the crema is noticeably darker with more consistent color and finer microbubbles. In addition, once the shot is pulled, the crema structure is more uniform and has more staying power.
In contrast, the vibration pump uses electricity rather than a motor, so the pressure oscillates, leading to a less smooth flow.
However, pressure is only one aspect of a perfect shot, and, even with a rotary pump, you need several things to get right to make great espresso.
The benefit of an espresso machine with a rotary pump is you can plumb it directly via the water line. This means that there’s no requirement to refill the water reservoir unless you want to, and there are no concerns over running out of water.
Vibratory pumps don’t have this possibility as they’re not designed to withstand pressure in the inlet. Therefore, you’ll have no option but to manually refill the water reservoir with a vibratory pump espresso machine.
You’ll likely notice the difference if you have a pressure pump in your espresso machine.
A rotary pump reaches full pressure, which is usually 8-9 bars depending on the machine setting, almost immediately after turning the machine on. It will also hold it at that level for the whole extraction.
On the other hand, espresso machines with a vibratory pump start on 2 bars of pressure, which gradually builds to 4 or 5 bars. Eventually, it will reach the same 8-9 bars as the rotary pump, but it takes much longer. Also, the pressure gauge needle might move back and forth between 1 bar or so. Finally, it usually takes longer than the rotary pump for the first drip as the pressure rises.
Vibratory pumps are a lot smaller than rotary pumps. For this reason, they’re often used in entry-level espresso machines that are quite compact, meaning they won’t consume much countertop space. In contrast, premium-quality prosumer espresso machines are much larger, partially because of their more sizeable boilers but also because of the internal space needed to house the motor and pump.
As we pointed out earlier, vibration pumps drive the piston back and forth 60 times per second, accounting for a large proportion of the noise. Overall, the sound they produce is both loud and sharp.
However, rotary pumps are quieter, and the noise is deep and low. Even though they also produce considerable noise, the noise levels aren’t higher than most coffee grinders.
The prices of the two pump types are considerably different. Espresso machines with vibration pumps are a lot less expensive. This is because there are around 40-50 global manufacturers of the pumps, and they are usually made with more plastic and less metal. Some of the best vibration pump brands to look out for are Ulka, Olab, and FLUID-O-TECH.
By contrast, rotary pumps have a solid and durable brass casing, metal bearings and metal shaft, some ceramic materials with carbon, and a motor. Naturally, this pushes up the cost. Meanwhile, there are not as many manufacturers of rotary pumps, which further inflates the price. But, again, FLUID-O-TECH is a reputable manufacturer of rotary pumps.
Overall, espresso machines with rotary pumps are usually more expensive than those with a vibration pump.
Durability And Maintenance
With a vibration pump, eventually, the coils will burn out. However, the pumps are easy to replace. How soon you’ll need to replace it will depend on how often you use the machine. You can expect it to last several years with normal home use of between three and five espressos per day. However, as we’ve already mentioned, vibration pumps are easier and cheaper to replace if something breaks.
Because rotary pumps are mechanical, they are more durable. The materials are also high-quality and able to withstand frequent use without deteriorating. That’s why cafes often have espresso machines with these types of pumps – they can make hundreds of cups of espresso a day without an issue. However, it’s worth keeping in mind that they are more expensive to replace, and it’s more difficult, too, as they’re harder to find.
Espresso machines with rotary pumps are the best option for commercial settings. Nevertheless, they are also worth considering if you are a domestic brewer, have the budget, and require the best possible espresso shots. That’s because they’re quieter and produce more consistent pressure.
Conversely, vibration pumps are less expensive, but they are louder. Their pressure is also not as consistent, so the espresso shot quality may suffer a little. Still, they are more than sufficient for domestic use and will work well for several years.
The espresso shots the two pumps produce many differ slightly in flavor. However, you are unlikely to notice the difference unless you pull the shots side by side and compare them. Overall, both pumps can produce perfect espresso shots when all the other variables are set correctly.