What is a Thermoblock?

August 1, 2023

For espresso enthusiasts, the design of an espresso machine can make all the difference in crafting that perfect cup of coffee. One innovative and efficient design that has gained popularity in recent years is the thermoblock. In this article, we'll delve into what a thermoblock is and explore its pros and cons when compared to traditional Italian heat-exchange and dual boiler brew systems. Two examples of espresso machines featuring thermoblock design are the Ascaso Duo and Quick Mill Silvano Evo.

What is a Thermoblock?

A thermoblock is a heating element integrated directly into an espresso machine. It serves the dual purpose of rapidly heating the water used for brewing and steaming milk. The thermoblock consists of a metal block with a network of channels or pipes through which the water flows. The heating element then surrounds these channels, quickly raising the water temperature as it passes through.

Pros of Thermoblock Design

Rapid Heating: One of the most significant advantages of a thermoblock design is its ability to heat water rapidly. This ensures that the espresso machine is ready for brewing in a matter of seconds, reducing the waiting time between shots.
Energy Efficiency: Thermoblock systems are energy-efficient, as they only heat the amount of water needed for each brewing cycle. This helps to conserve energy, making them a more eco-friendly option.
Compact Size: Espresso machines with thermoblocks tend to be more compact and lightweight, making them suitable for smaller kitchens or spaces with limited counter space.
Budget-Friendly: Espresso machines equipped with thermoblocks are generally more affordable than those with heat-exchange or dual boiler systems. They offer a budget-friendly option for coffee lovers who desire fast and efficient brewing.

Cons of Thermoblock Design

Temperature Stability: Thermoblocks might not offer the same temperature stability as heat-exchange or dual boiler systems, especially when brewing multiple shots back-to-back. This could affect the consistency of the espresso extraction.
Limited Simultaneous Tasks: Since the thermoblock heats water for both brewing and steaming, performing both tasks simultaneously might not be as efficient as with dual boiler systems.

Comparison to Traditional Brew Systems

Italian heat-exchange and dual boiler systems are renowned for their temperature stability and the ability to brew and steam simultaneously. Heat-exchange machines have a separate heat exchanger to maintain a consistent brewing temperature, while dual boiler machines have two separate boilers for brewing and steaming, eliminating any wait time between the two tasks.

While thermoblock systems offer rapid heating and energy efficiency, they might not match the temperature stability and multitasking capabilities of their traditional counterparts. However, they present an excellent option for those seeking a more budget-friendly and compact espresso machine without compromising on speed and convenience.

The Ascaso Duo and Quick Mill Silvano Evo are both fantastic examples of espresso machines featuring thermoblock design. They deliver quick and efficient brewing, making them ideal choices for espresso lovers who value convenience and affordability.

Conclusion on Thermoblock Technology

In conclusion, the thermoblock design in espresso machines offers a viable solution for those seeking fast heating, energy efficiency, and a more budget-friendly option. However, it's essential to weigh the pros and cons and consider your brewing preferences before making a decision. Whether you choose thermoblock, heat-exchange, or dual boiler, the ultimate goal is to enjoy that perfect cup of espresso that fuels your passion for exceptional coffee experiences.

Solid piece and great service!

A great buy for beginners, a solid machine. Great service from Nick and super fast shipping! We’ll definitely come back here for an upgrade later on.

Outstanding Machine (But Takes Practice)

This is my first manual espresso machine after starting with a cheap full auto and later upgrading to a semi-auto BES870XL. I love the sheer amount of control that I have over my shots, from the pressure the machine brews at to the amount of water that goes into the shot (more so with a double), pre-infusion time, and flow of the steam coming out of the wand. It takes a lot of time getting dialed in right to produce a good shot, and I am still working on my technique, though it has improved greatly in the past few weeks that I've had this machine.

Out of the box:
I'll start with the most disappointing thing for anyone who reads this: The tamper this machine comes with is a cheap, flimsy, plastic 48mm disc that doesn't even cover the surface area of your 49mm portafilter. If you don't have one already, save yourself the extra wait and get yourself a nice, heavy 49mm tamper when you buy this (I got a solid stainless tamper by Silmur and it's perfect) and throw the plastic one into the trash upon arrival.
Now for the good: Everything was well-packaged in molded styrofoam to minimize the chance of impact damage. Everything came out looking shiny and beautiful with no damage. Assembly was pretty straightforward, and the owner's manual gives you just enough information to get started. Disclaimer: the manual does not tell the user how to adjust the pressurestat if you find that your machine is not in the right zone out of the box, or if you really want to fine-tune your extraction. But fear not: simple but tedious pressurestat adjustments are a quick Google/YouTube search away (butter knife and small ratchet with phillips and flat head bits to get the job done not included).

Brewing with this bad boy requires a ton of patience. If you're new to manuals, do not expect to pull amazing shots right away. Even semi-autos have their nuances, though not nearly as many. First, make sure that you can see the meniscus (that bottom line at the top of your water) in the sight glass. This will ensure that your boiler is neither under nor overfilled. It doesn't take long to heat up and get to pressure. Once it's ready to go, the rest is up to you (take lots of notes; it helps!). After a few weeks of active use, I've just about gotten it down (until I get different beans, that is). The steam wand is another well-designed piece of this machine, and produces the silkiest microfoam I have ever made. You control the output, and it is immediate steam on demand. Do let some out to get the wand up to temp and avoid it shooting straight hot water into your pitcher before frothing it up. Back to brewing: It does seem to run a bit hot, and I've read that the general consensus is that the ideal brewing temperature is right when it gets up to pressure, and then after that the user should to apply a cold cloth to the groupset to keep temperatures down and avoid burnt shots. I'll start following that advice and see how my extraction improves.

I've been having a ton of fun with this machine, and don't think I could ever go back to anything short of a manual espresso machine after this experience. It's definitely one of my favorite additions to my coffee-making collection, and I'll probably love it even more when I finally do pull that perfect shot.