Coffee Data Science

A Taxonomy of Lever Espresso Machines

Grouping machines by functionality

Published in

Towards Data Science

4 min readAug 17, 2021

I have loved lever machines since I happened upon one in my mother-in-law’s basement. We were looking through a backroom, and I stumbled upon la Pavoni. She let me have it, and I cleaned it up. However, I still hadn’t upgraded my grinder to truly appreciate it. Little did I know, only a few weeks separated me from getting another lever machine and the love of my coffee life, the Kim Express.

I bought the Kim Express from an estate sale, and I didn’t fully understand how rare the machine was. Over the years since, I have bought La Peppina, Enrico of Italy (ItalianStyle), Flair, Kompresso, and a few more Kim Express machines.

Lever machines are distinct from other espresso machines because the user has direct control over the flow rate with the lever. That is the basic concept, but they have evolved quite a bit.

Lever machines fell out of household fashion once water pump machines became available and cost effective. A lever machine still gives the control that costs much more money for a pump machine of the same caliber, but they require a bit more attention to detail.

Grouping Lever Machines

I have studied a few of the other machines available. While there are resources to read about old machines, particularly Francesco Ceccarelli, I haven’t seen the machines categorized or grouped together based on their similarities and differences. From my own experiences with my machines, I know they all have the quarks, and I wanted to create a taxonomy to help understand which machines functioned most similar to one another.

I used Francesco’s list plus some machines not on that list to make this chart. All the machines in this chart are examples for machines in that group. Often there were many more that I didn’t include. My aim was to show their main differences.

Definitions

Lever

A lever machine can be driven by your hand or by a spring. In the case of a spring driven lever, you hold the handle to slow the lever’s movement. Both require action, but a spring level could be pulled and released while a hand lever has to continuously be pushed:

Hand Lever: water flow directly linked to pushing down on the lever.

Spring Lever: water flow inversely linked to pushing down on the lever.

In the category of no boiler, one example (Aram) uses a turn screw to apply pressure, and another (Kompresso) uses hands to push the plunger. Both of these methods still have a direct link between the person and the flow rate during the shot, which is why I would still consider them in the category of lever machine.

Left: La Pavoni, an example of a Hand Lever machine. Right: Kim Express, an example of a Spring Lever Machine.

Boiler

Three boiler options exist with the option to have the water temperature PID controlled. Higher end lever machines have PID controllers to maintain a certain water temperature:

Left: Closed boiler, Center: Open boiler (the lid is not sealed), Right: No boiler

La Peppina is particular interesting because while it is a lever machine, it’s function crosses over with pump espresso machines because you have to pump the lever a few times. You can still control the flow with the lever once the puck is pressurized with water.

Temperature Control

Here are only lever machines with water temperature control. I may have forgotten a few as these are just examples and not exhaustive list.

I really enjoyed reading up on so many lever machines. Many from the 50’s and 60’s seemed like copies of La Pavoni or La Peppina. I enjoyed the variety of machines, and I like trying different lever machines as it gives me better insight into my favorite machine.

If you like, follow me on Twitter and YouTube where I post videos of espresso shots on different machines and espresso related stuff. You can also find me on LinkedIn. You can also follow me on Medium.