Hello Vesuvius

The world of quality, home espresso is not unlike other hobbies. Start out with modest intentions, and pair that with equipment that mimics that modesty. Several years later, look back, and realize that you’ve lost nearly all sense of reality, spending far more money and time than ever predicted.

The purchase of the ACS Vesuvius was a long time and coming. I spent nearly 10 good years with a Quick Mill Anita: A simple but robust machine that was trustworthy, and to this day still makes fantastic espresso. It paid for itself many times over, but the last few years I was getting the itch to look for a next step up. More on the Quick Mill Anita in an upcoming post.

Why the ACS Vesuvius?

In my search for the next step up, I initially considered a Slayer – a machine commonly put at or near the top of the prosumer offerings of high end espresso machines. It differentiates itself esthetically, and to a certain degree, mechanically. Few would argue against the result: It is a beautiful, high quality machine. I went so far as to visit the headquarters in Seattle a few years ago. The good folks there showed me around the facility, and answered all of my questions, and would still love to have one. My visit was prior to the acquisition of Slayer Espresso by Gruppo Cimbali in late 2017.

The Vesuvius started surfacing more and more when I began revisiting the idea of a new espresso machine last year. I’ve had a good relationship with the staff at Chris’ Coffee, and they sang its high praises. Listening to them was akin to trusting a mechanics on the reliability of car manufacturers. They are on the front lines of the repairs of a wide variety of espresso machines, and their input was valuable. Ultimately, what drew me to the Vesuvius was its impressive build quality, specifications, and the ability to vary the rate of pressure when pulling a shot. All for a relatively good value when compared against other options.

My Vesuvius in action


I’ve spent nearly six months with the Vesuvius, and wanted to share some observations that stand out the most. The good, bad, and indifferent sprinkled across a variety of design and operational elements of the machine.

  • Aesthetics. A pleasant surprise was how the Vesuvius looks in person. The images found online certainly give the impression of a nice clean look, which I appreciated. In person it is much more elegant, and impressive. And the wood accented valves and portafilter looked a bit cheap in photos, but in person they are actually a real highlight of the system.
  • Weight. While it might have a similar looking form factor to other prosumer machines, it is a beast when viewed in person. The shipping weight comes in at 156lbs (70kg), and came in on a pallet. You won’t be lugging this to your friend’s holiday party.
  • Pressure Profiling. This has been as interesting (if not more) as I was suspecting it would be. The control of the effective flow through the puck is extraordinary, and relatively easy to do considering the relatively basic touch screen controller. The ability to control flow is something that was extremely rare in the prosumer market – until Slayer came along. With mounting pressures from machines that do pressure profiling like the Vesuvius, Slayer plays it a little fast and loose with their marketing and the benefits of their needle-valve technology in comparison to other methods used, but I’ll save that for another post. It is clear after using the machine, that the pressure profiling abilities on the Vesuvius are absolutely impressive, and it is fun and educational to learn how different profiles will influence the outcome of the shot. More details on pressure profiling with the Vesuvius in an upcoming post.
  • Pump. The Pump certainly sounds different than machines using rotary and vibratory pumps. What it offers is high levels of control based on the conditions that the PID is seeing. The Vesuvius even allows for the independent adjustment of the pump acceleration speed when it senses the need to change. This can play an interesting factor when working with pressure profiling.
  • Brew Head. While it is a classic E61 brew head, what is interesting is that the pre-infusion chamber of the brew head (the lower portion of the E61) is disabled since all pre-infusion is handled by the Vesuvius. Also nice is that the exhaust port for the brew head is extended down to where it almost touches the drip tray. This minimizes overspray.
  • Overall programmability. The Vesuvius has a level of adjustability that I didn’t appreciate until I started using it. Adjustments to the brew boiler, steam boiler, PID settings and temperature offsets can all be changed easily. As an added touch you can define when the machine should turn on and off for each day of the week. I do wish however that the touch screen display was more modern, and typically of what we would see in devices in 2019.
  • Steam Pressure. Very impressive. Steam pressure will start off at 1.6 to 1.7 bar, and by time 8 ounces of milk hits 160F degrees, it is still at 1.0 or 1.1 bar. And it continues to hold that pressure for what seems like an indefinite period of time. The Vesuvius ships with a three hole tip that I find steaming milk to be very easy. Start out right in the middle of the pitcher with a slight tilt inward. Slightly submerge tip when milk hits about 80F, and it develops a nice folding, vertical vortex all the way up to drink temperature. The steam power and the choice of the tip really works well.
  • Steam wetness. Noticable, but workable. The amount of condensation build up that needs to be purged almost makes one believe there is something wrong. Purging will result in streams of water shooting out of the steam tip before clearing itself out. I even find some follow-up spitting that occurs. This seems to simply be the result of several design choices not commonly found in other machines. The nicely insulated and isolated boiler uses a plumbing layout to the wand that might be more lengthy, as well as using stainless steel tubing instead of PTFE tubing. The Vesuvius also uses a silicon lined no-burn steam wand, which are notorious for promoting condensation. I had a no-burn steam wand on my old Quick Mill, and never experienced condensation like I see with the Vesuvius, which makes me think it is a collection of factors contributing to the issue. Some of the higher end machines choose not to use no-burn steam wands, opting for a single lined stainless wand. I’ve bumped up the boiler temperature slightly, and ensured the setting allows for the lowest level of water in the boiler. This has helped, but it hasn’t eliminated the issue.
  • Condensation is all about differentials in temperature (induced by heat or pressure), water vapor content, and characteristics of the barrier. More investigation will be needed in order to determine the most significant contributor to the condensation. I’ll save that for another time.
  • Steam wand. The wand is a bit of an odd shape, or at least to what I was used to. Not unworkable, but I suspect there is a different design out there that could be better. Apparently some Vesuvius owners have made the wand from a La Marzocco GS3/GB5 work. I may give that a try at some point.
  • Drip tray. It’s a large drip tray that can be plumbed, but it is a bit awkward. For an non-plumbed arrangement, I don’t like standing water in my drip tray, so I routinely empty it after my morning and afternoon shots. The assembly of the tray, and the grill are a bit clumsy.
  • Heat up time. Traditionally, most prosumer espresso machines (both single and dual boiler units) have been known to take a fair amount of time to heat up. There is a lot of mass to these systems, and it is natural to wait a good 45 minutes or so for the heat to permeate through all of that metal. While I still typically wait for that long with the Vesuvius, its ability to be ready for a pull is extremely fast. A 200F degree brew temperature take about 8 minutes and full 1.6 bar steam pressure shows up in about 13 minutes. Temperature stability is also very good.
  • Water reservoir. Someone finally decided to put a water reservoir on the side! Great! No more rotating the machine around just to fill it. However, adding water is still a bit awkward, and is motivation to get it plumbed in. The water tank is also wired in to connect to the low water sensor, which makes detaching this for periodic washing of the reservoir more difficult than it should be.
  • Option for plumbing. I really like the approach ACS used for the design of the plumbing the water line. The plumbed line to the Vesuvius feeds the water into the reservoir, not directly to the system. This eliminates line-pressure considerations found when plumbing in other machines, but of course requires the use of a tank to act as the proxy.
  • Bottomless portafilter. I’ve had excellent results with the 18g basket that comes with the bottomless filter. I’ve experimented with a 18g VST basket, and found that at this time, I prefer the results of the OEM basket. I have not tried the 20g VST filter yet, as those who have tried it with the Vesuvius bottomless filter have stated that the espresso will have a tendency to wick its way onto the handle. So contrary to popular practice, I continue to use the OEM basket to produce better results.
  • Shower screen. I had an extra IMS “E61 200 IM” shower screen laying around, and decided to try that against the OEM shower screen. I expected better results with the IMS since it wasn’t as deep as the OEM model, but I found after quite a bit of experimentation, that once again, I preferred the results of the OEM shower screen. I may try another model of an IMS shower screen, but will continue to use the OEM version for now.

Early Production Adjustments

The early production runs of Vesuvius machines had a few issues with them that were not abnormal to any first generation product. Some early machines originally shipped with an undersized plug, which caused a few electrical issues, and was addressed relatively quickly. The Vesuvius and some other high-end machines used a pump that wasn’t capable of maintaining pressure. This was a flaw of the pump manufacturer, not the machine, and has since been addressed.

An updated version of the Vesuvius has been shipping for some time now, which includes those fixes, along with a few other improvements. This includes more robust vacuum breakers, an improved water detection sensor, and using metal tubing in place of PTFE tubing.

The verdict

Overall, I’ve been thrilled with the Vesuvius. I’ve had to adapt my workflow a bit to match the capabilities of the machine, but the output, and the build quality is fantastic. Yes, there are a few things I’d like to see them change, but overall, it delivers on everything promised, with features that typically demand a much higher price than what the Vesuvius can be purchased for.

Now, time to upgrade the grinderā€¦


  1. Interesting review,

    You still using the OEM basket? I haven’t even tried mine, just fitted my VST straight away.


    1. I also use OEM basket and naked filter I think it work really well! Very interesting review, please let me know if you get less condensation…although my level is amateur yet, I enjoy every day with excellent coffees.
      My grinder is niche zero.

      Regards from spain!


      1. Thanks for the feedback! …And yes, the condensation is clearly noticeable on the steam wand, but for now, I’ve simply chosen to accept it, because it’s an amazing machine. Will be hoping to pick up a Niche Zero sometime soon as well.


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