About

A Brief History

My name is Tommy, and I invented the Leverhead Espresso machine. This is a bit embarrassing, but it’s the truth: all I really wanted to do was learn how to make latte art. I’m so cheap though that I decided I would build my own machine in order to save money. Well, save money, have a fun project, and make something that was better than what I could already buy. I felt the other stuff out there left a lot of room for improvement.

I’m also a YouTuber (my channel is called One Minute Workbench), and I thought this machine would be a fun, inexpensive, quick, and easy project to add to my channel. I was wrong.

I anticipated this project would take a couple of weeks and cost less than other manual machines I’ve seen on the market. Instead, I’ve been working on this for over a year, and have spent…well, a lot…of money on materials and tools.

Okay, so, I was a tad ambitious. Not only did I want to build my own machine, I wanted it to be better than everything else out there. On my channel, it is often my goal to produce something better (or at least comparable) for less money. In this case, I gave up on the “less money” idea, but stuck with wanting to make “something better”.

For me, making something better meant making something with a streamlined workflow (less time, less steps, less fiddly…more like the steps involved in using a semi-automatic machine). Less time spent making espresso means more time spent enjoying it.

It has been a long road, but the machine is finally here, and I’ve learned a ton about material science, espresso, and the physics involved in the process. My hat goes off to all those who came before me, especially those who managed the very first extractions. It must have tough.

Oh, and in case you’re wondering, I’m still not very good at latte art 😂

Innovation

I realized earlier on that I needed to do things differently. It became clear that I wasn’t going to be able to just streamline what others have already done, and somehow wind up with a better machine. To the credit of other engineers, they’ve pretty much already streamlined everything about standard espresso equipment, and have taken it as far as it can go.

The big problem was thermal management. Most materials that are strong enough to withstand the incredible forces of the espresso making process have high thermal conductance. Because of that, those materials steal heat from the water. Most machines use metal to withstand those forces, but again the side effect is that your machine is basically a giant heatsink.

Automatic and semi-automatic machines overcome this with an electric heater. Most manual machine makers suggest that you bring the components up to brewing temperature through various preheating routines. I’ve seen things like filling a bowl with boiling water, disassembling the brew head and putting the components in there for several minutes. I’ve seen others suggest that you disassemble the brew head from the machine and place it on top of a steam source for a few minutes, then reconstruct those parts once they’re up to temp. Most machines have a giant metal piston, and some of those can’t be disassembled at all. The only way the piston in those machines can be preheated is by making 1-2 “primer” shots.

To build a better machine, I needed to eliminate the preheating process, which meant I needed to actually solve the problem of heat loss, not just work around it.

A Longer History

At first, I tried going away from metal as much as possible, and my earliest prototypes were built almost entirely out of wood. I even built one around the AeroPress. It actually made really good shots!

It wasn’t a great machine though. Certainly not better than was already out there. The espresso was good, but the experience was cumbersome, and the machine itself was HUGE.

Wood is amazing in that has relatively high strength and extremely low thermal conductivity…lower than silicone even. So it seemed like I should keep going down that road, at least for a while.

Wood doesn’t resist moisture very well, and isn’t dimensionally stable. Plywood is more stable and stronger than regular boards, but it still has trouble resisting moisture. Finishing (with lacquer for example) helps, but areas that are repeatedly subjected to steam, will eventually fail.

Accepting the limitations of plywood, I continued designing with it so I could focus on the more important issue; designing seals that helped solve the problem of heat loss.

In this case, the wood did fine, but the seals failed.

I can’t even articulate how difficult it was to design seals that sealed the deal, but trust me…it was beyond arduous, and took nearly 3 months of long days. The COVID pandemic gave me lots of time at home to focus on solving the problem. On the plus side I learned lots about casting food grade silicone.

Where are we now?

With the seals designed, a successful prototype finally came together. It was strong, didn’t leak, and created the type of thermal management necessary to improve the workflow. It reliably preformed its duties as my daily espresso maker for about 6 months. This little gem:

It even held up as the espresso machine for a pop-up coffee shop. We served about 40 shots of espresso that morning, and the machine worked beautifully. It was a fun experience, and a testament to what the machine could really do.

That machine is actually still in good working order, but I wasn’t satisfied that it would be something that would last daily users for years on end. Like so many designers before me, I needed metal for strength, but I wasn’t willing to accept poor thermal management or time-consuming preheating routines.

The Final Piece of the Puzzle

I finally found a way to use metal for the brewing platform, and keep it from stealing heat. I call this technique thermal isolation. ONLY the parts of the machine that must touch hot water do. And those parts either have low thermal conductivity, or are isolated from other parts of the machine. It does a very good job of keeping the heat where it belongs, which means almost no preheating is required. When preheating is desired (for lighter roasts), it’s very easy, and takes only a few seconds.

With the innovative seals and thermal isolation technique working together, the Leverhead has achieved a truly streamlined workflow. No disassembling the machine, no dunking in hot water, no shooting “primer” shots, or any other fiddly routines. It works nearly the same as a semi-automatic machine with the exceptions of adding a shower screen, pouring your own water, and pulling the lever. And because the components that receive the most stress are built from metal, the machine will last for years to come (honestly, it’s built like a tank).

If you made it this far reading this article, thank you! I hope you found it entertaining, and maybe developed an appreciation for what a crazy ride this has been. It hit my wallet hard, took a year of my life, brought me tears, and now finally brings a smile to my face. I hope it brings one to yours as well 🙂