A Barista's Review of the La Marzocco KB90 Espresso Machine

The KB90 is the newest member of La Marzocco’s impressive lineup of espresso machines. Developed as an evolution of the popular Linea PB model, the KB90 boasts the features, design, and functionality necessary to maximize a barista’s workflow without the physical strain and fatigue caused by traditional espresso machines.

But even with the latest technology and ergonomic features, does the La Marzocco KB90 offer the best value and drink quality for your coffee shop?

The La Marzocco KB90 espresso machine couples its reputation for reliable design and functionality with the ergonomic features baristas need for espresso quality and career longevity. We spoke with Matthew Delarosa, owner and founder of Ironsmith Coffee Roasters, about his experience using the KB90 in his coffee shop.

In our guide, you’ll discover:

  • How the KB90’s revolutionary portafilter design improves barista ergonomics
  • Which espresso machine features contribute to an efficient workflow, even during the busiest of rushes
  • What maintenance a KB90 espresso machine needs to continue running in top shape

By the end, you’ll know if the La Marzocco KB90 will be the perfect fit for your coffee shop.

An Overview of the La Marzocco KB90

After the Linea PB revolutionized La Marzocco’s lineup of espresso machine technology, there was one last challenge to tackle: barista ergonomics.

Those who have worked as a barista know how much strain repetitively cranking a portafilter in a grouphead can cause on a wrist. And, past steam wand designs left baristas with accidental burns and injuries if used improperly. 

In 2019, La Marzocco launched the KB90—named after Kent Bakke, La Marzocco’s former CEO and current Chairman of the Board—to combat barista stress injuries while optimizing bar flow and espresso quality.

Based on the groundwork laid by the Linea PB, the La Marzocco KB90 iconic new features include:

  • Straight-in portafilters — The KB90’s innovative portafilter design was developed to reduce barista fatigue and strain up to 12x, effectively enhancing barista performance and overall bar flow efficiency throughout the day.

  • Independent brew boilers — This espresso machine takes temperature stability to the next level with a dedicated brew boiler for each grouphead, which allows baristas to dial-in parameters for individual coffees.

  • Auto brew ratio / Drip prediction — Digital scales installed in the drip tray automatically stop extraction when the desired mass is achieved. La Marzocco’s new drip prediction technology uses an algorithm to enhance espresso accuracy.

  • Steam flush — Between shots, the KB90 automatically sends a burst of steam and hot water flush, ensuring a clean grouphead environment without added barista effort.

  • Pro touch steam wands — Eliminate the risk of on-the-job injuries with vacuum-insulated double-walled steam wands that maintain high-pressure steam while remaining cool to the touch.

  • Easy rebuild steam valve — Steam valve repairs and maintenance are made easy with access in the front of the machine and no removable parts.

  • Like many of its espresso machine counterparts, the KB90 also boasts standard La Marzocco features such as:

    • Dual boiler system
    • PID temperature control
    • Saturated group design
    • Digital display
    • Barista LED lights

    Available Modifications

    In true La Marzocco style, the KB90 can be modified to accommodate your coffee shop’s desires and bar flow.

    Model Size

    Choose between a 2 or 3 group machine.


    With the KB90, you can opt for auto-volumetric (AV) extraction or auto-volumetric extraction using La Marzocco’s Auto Brew Ratio technology with integrated drip tray scales (ABR.)

    Discover the latest prices for La Marzocco’s KB90 espresso machine (and learn more about available wholesale discounts) here.

    A Professional Barista’s Thoughts on the La Marzocco KB90

    Matthew Delarosa is the owner and founder of Ironsmith Coffee in Encinitas, CA. Ironsmith Coffee installed the KB90 in January 2022 to seamlessly accommodate the large volume of orders they receive, without sacrificing drink quality for efficiency. 

    We spoke with Matthew about his transition from the Linea PB to the KB90, his experience with the espresso machine thus far, and what other coffee shop owners should know before investing in the KB90.

    How do first-time baristas do with the machine?

    M:I think my baristas adapted fairly well from the Linea PB to the KB90. Leading up to it, I explained the differences in bar flow and the ergonomics of the machine to them. While there’s a fast learning curve, experienced baristas will have to break some bar flow habits with the KB90’s straight-in portafilters. But once that was established, it’s been great from there on.”

    How does the machine perform during a busy rush? Average day?

    M: “Amazing. Before this, we had the Linea PB. So, we were accustomed to the efficiency of the machine, the auto-volumetric settings, and other similar features. I’d say the KB90 performs even better, especially with the individual boilers for each grouphead. With this capability, it keeps temperature really stable and performs extremely well in the high-volume rushes we get.”

    Are there any features of the KB90 that contribute to an effective workflow?

    M: Outside of the ergonomic benefits of the straight-in portafilters, the individual group boilers have helped our bar flow tremendously. And, the cool-touch double-insulated steam wand handles are great too.”

    How are the machine’s ergonomics for baristas?

    M:The KB90 is known for the straight-in portafilters, but there are so many little details about the machine that allows for a more ergonomic experience for baristas.

    We use a two-person system for our bar flow, with one barista steaming milk on the left side and one pulling shots on the right. Previously, if the second person needed to use the left side grouphead, they might accidentally interrupt or bump into the other barista, messing up the milk quality in the process. With the KB90’s design, this is no longer a problem.”

    What should first-time users know about using this machine?

    M:There are more moving parts. You need to have an appreciation for and understanding of day-to-day cleaning and maintenance. While the machine makes workflow easier and more efficient, there are other parts of the day-to-day cleaning you’ll need to incorporate into your coffee shop’s processes to ensure the longevity of this machine.”

    What’s the standard maintenance timeline for this machine? How often are repairs required?

    M:So far, we haven’t had to do any repairs or maintenance. We auto-backflush our machine daily. If we have a busy day, we’ll backflush midday as well. The KB90 allows you to auto-backflush all three groupheads in a sequence too, which is beneficial.

    Most of our maintenance and cleaning is focused on the aesthetics of the stainless steel machine. We use microfiber towels to clean and are meticulous about making sure our machine is spotless.”

    What’s it been like implementing repairs without a technician? Is this something the staff can do?

    M:It really depends on what repairs need to be done and the quality of your water. Back when we had the Linea PB, we had clogs and corrosion due to water quality, which required us to take apart the groupheads, clean them, and replace certain parts due to buildup. We did upgrade our water system when we got the KB90, so I’ll be staying more on top of that!

    Personally, I’m the type that likes to take apart the machine, check on things, and flush out the steam boilers. However, I recommend having qualified technicians look at, diagnose, and repair your problem before you start taking apart the machine.”

    Can you describe some of the common problems you’ve experienced with this machine?

    M: “We had the steam wand pressure setting a little low at first, but we quickly fixed it to accommodate our bar flow. Due to our prior experience with the Linea PB, we didn’t have a difficult switch to the KB90 from a technical or maintenance perspective.”

    In combination with a quality grinder, how does the espresso pulled and milk steamed from this machine compare to others you’ve used throughout your career?

    M:Just as good, if not better! We also upgraded to Mazzer Kold S grinders to set us up for the best performance right out of the gate.”

    Do any specific machine features contribute to drink quality?

    M:We were already used to using La Marzocco’s auto-volumetric features with the Linea PB. With this feature, we’re always confident about the quality of our shots, no matter how busy the café gets. Combined with the new grinders for a consistent particle grind size, we’re positioned for excellent drink quality at all times.”

    Is there anything else that someone who’s considering buying this machine should know before they commit?

    M:One thing to note is that you cannot change the pressure on this machine like a La Marzocco Strada. If this feature is important to you, the KB90 may not be right for your shop.

    The KB90 is made with efficiency and workflow in mind, while still maintaining superior drink quality. This design allows baristas to multitask. This machine definitely allows you to be the most efficient by far.”

    The La Marzocco KB90: In Review

    There’s no doubt the KB90 is the most ergonomic and efficient La Marzocco espresso machine on the market. Between the innovative portafilter design, independent group boilers, and auto-volumetric extraction, this machine combines drink quality and efficiency with ease.

    Before you add the KB90 to your cart, let’s take a look at the machine’s pros and cons.



    Straight-in portafilter design reduces barista fatigue and wrist strain

    Newer technology requires more parts, leading to the increased need for qualified technician assistance

    Independent grouphead boilers ensure temperature stability and control

    Not available in 1 or 4 grouphead models

    Enhance extraction accuracy and efficiency with Auto Brew Ratio and Drip Prediction technology

    Customizable colors or finishes not available

    Cool-touch steam wands ensure baristas can safely steam milk at the desired pressure throughout each shift

    Easy rebuild steam valves make repairs and maintenance simple with quick access 

    The La Marzocco KB90 is a great option for coffee shop owners interested in purchasing an espresso machine that:

    • Focuses on the well-being of baristas with revolutionary ergonomic features
    • Maintains consistent boiler temperatures throughout a busy, high-volume shift
    • Takes espresso extraction to the next level by leveraging technology

    Think the KB90 is perfect for your shop? Check it out and ask us about available wholesale discounts for all your espresso gear needs.