Video Overview | La Marzocco KB90 AV Auto-Volumetric Espresso Machines

Video Overview | La Marzocco KB90 AV Auto-Volumetric Espresso Machines

Oct 17th 2019 Written by meredithlangley

Bye-bye, barista wrist! Smart workflow and ergonomics are the name of the game for La Marzocco's KB90 Espresso Machine. The new straight-in portafilter design requires no awkward wrist twisting motions, providing a much gentler experience for your barista's joints. The KB90 also comes complete with a suite of new features, including the brand new Pro Touch wands, as well as optional offerings like drip tray scales. Get to know the KB90 in this video, as Steve shares on this barista-friendly machine from La Marzocco.


Hey folks, this is Steve with Prima Coffee here. Today, we're taking a look at La Marzocco's KB90 espresso machine, which introduces their new straight-in portafilter design. A much simpler mechanism for locking in a portafilter that will help save your wrists. So, the KB90 has quite a few new features that are being introduced to La Marzocco's commercial espresso machines. The first, of course, is that hallmark straight-in portafilter design. We've got another...a nice set of new features as well that we'll talk about as we introduce the rest of this machine. But let's first talk about capacity. In the back, we have a large steam boiler. On this 2-group machine is a 7-liter steam boiler with 3000 watts of power. We also have independent brewing groups. Now each group has a 1.3-liter brew boiler attached to it. They are saturated groups as all La Marzocco's espresso machines are. And each group and boiler has an 800-watt heating element on its own. A three-group machine would have, of course, a third group and boiler, and a larger steam boiler at 11 liters with 4,000 watts of heating power.

La Marzocco KB90 AV Auto-Volumetric Espresso Machines | 2 or 3 Groups

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Ergonomic straight-in portafilter design to reduce repetitive stress injuries

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Now, the machine is only available in two or three groups. It is also available in auto-volumetric or ABR, which would be basically a machine that has scales. We call it ABR because that is auto brew ratio, but it can actually be run in ABR auto brew ratio, mass mode just by weighing onto that scale, or as an auto-volumetric machine. So it has all three of those capabilities. This is the ABR model that I have in front of me. We have the drip tray scales. So we'll talk a little bit about those features and how to set things up. Now, you'll notice that I have these sort of Linea-PB-style buttons above each group. I have two dosing buttons plus a continuous or semi-auto dosing button. Now, the two programmable dosing buttons both have short-press and long-press capabilities. So just pressing the button once will give you one program dose, holding the button down for about two seconds will give you another program dose. Both of those functions are available for the mass mode and volumetric mode. In brew ratio mode, we actually have a little bit of a different functionality that I'll get to in a bit.

Again, we also have this smart new straight-in portafilter design. The way that this works, we have a newly designed portafilter, this is not compatible with legacy La Marzocco portafilters, you have to have ones designed for the KB90. Where we have this rail system where you slide the portafilter straight in until it stops, it hits some rubber bumpers, and at that point, you can lift the portafilter handle up to lock it in place. We also have a quick-release mechanism, which is conveniently accessible just by using your thumb. Just push that down and that's how you will pull your portafilter back out. Very, very easy to use. And again, it really helps save the strain on your wrist. The motion of inserting a portafilter at an angle and twisting until it's tightly locked in on a traditional group design that can actually lead to some pretty serious repetitive stress injuries. And a lot of baristas can probably tell you that yes, they definitely experience some pain in the wrists after busy shifts, especially after a few busy weeks. That stuff tends to lead up... to build up and lead to some pretty painful joints and injuries.

So, this new design is actually very, very light on motion. It's pretty natural in terms of how you lift the portafilter and lock it in place. It does not require a lot of strength to use or to release. So, they put a lot of thought into it for sure in terms of making it much easier to use as a barista. We also have a couple of new developments in terms of how this overall group works because of this system. One thing that you'll notice is when the portafilter is locked in, the portafilter is still kind of wobbly and wiggly, and that that's actually because the group screen and gasket are pneumatically lowered or hydraulically lowered when the pump is actually engaged. So, right now, my portafilter is kind of wiggly, but if I hit one of my dose buttons, it becomes much firmer because that whole system has actually engaged and been pushed down by the pressure of the water. That will ideally mean that your group gaskets last much longer. You do not have the extra torque that a lot of baristas tend to throw into the portafilter handle when they're locking in. It's a much gentler introduction of the gasket to the top of the basket.

It should last quite a bit longer. We don't really know for sure how long at this point, but probably maybe two to three times longer just because you aren't torquing on that gasket a few hundred times a day. Another interesting thing that they've added, you'll see right now as I remove my portafilter, is what they called the steam flush. So, after pulling a shot and after removing the portafilter, the machine will automatically go through a cycle of blowing steam through the dispersion screen to remove debris as well as flushing with some hot water afterward. That is programmable. You can turn it off or turn it on. You can also change how long each section of that steam flush, the steam and the hot water, actually runs for. So, if you want to extend the water flush, for example, so you can rinse out your portafilter basket after knocking out your puck, you can do that. Ours is running at about two seconds for each. And this is a really nice handy feature because it's going to help keep everything nice and clean. You will still have to go in there with a rag, or a spray bottle, or a brush, or anything, just to help clean off the extra debris.

But that is going to be a nice step that the machine goes through after you pull every shot to make sure that pretty much everything is staying clean and your shots are tasting the best they can. Just to cover some of the other features that we have. We have new pro-touch steam wands. These are dual-wall, stainless-steel, vacuum-insulated wands. Which means that they stay very cool to the touch even after long periods of steaming. Now, the steam tip will still get quite hot. And the first maybe inch or so of the metal on the wand will also get pretty hot or warm to the touch. And, of course, any exposed metal that is submerged in milk during steaming will be about steamed milk temperature. So, it's not going to stay completely cool to the touch at all times, but you can turn the steam on and hold on to the wand quite comfortably. It does not get very warm through normal use. So that's a really nice feature. You'll obviously notice we don't even have rubber grips on the wand because you really don't need them.

It stays very, very comfortable to move around. And even if you're bumping into it accidentally, it's not going to burn you quite as much as some more traditional steam wands would. In addition to that new pro-touch wand, we actually have new steam valves and this is going to be more for the technicians out there. But we have shut-off valves for each steam wand at the steam boiler and these steam valve assemblies actually pull straight out so you can service them without taking the machine down. You can pull the whole valve assembly out, change out your o-rings, lubricate things, put it back in, lock it in place, and basically just a few minutes, you have rebuilt your steam valve without having to take down the whole machine and then interrupt service. So, very, very convenient way to keep that maintained and operating at its best. Now let's pull a shot and just walk through what it's like. I actually have two different modes set up on each group. I have mass mode over here on my right and I have brew ratio on the left. I'm going to pull a shot in mass mode first just to demonstrate what that's like.

Now mass mode just means that my programmed doses are for achieving a certain mass in the cup on the scale. I am actually going to weigh my dry dose here, which I don't have to do when using the brew ratio mode. So I've got about 19 and 1/2 grams of coffee in the basket and I'm looking for about 45 in the cup. So one quick thing to note for either brew ratio or mass mode is that you probably want to have a receptacle cup or shot glass or something on the weighing platform before you start your shot. And that is just because there's a taring period. You can actually adjust that in the settings. But the first two to three seconds are usually the tare period, where the scale is registering what the weight is of the cup or shot glass already on the platform and then zeroing it out to prepare for the beverage. It is best, in our experience, to have something on that platform before the shot starts because sometimes you might be maybe a gram off or so when you put something down during that tare period. It's possible that that can be improved over time, but at least in our experience, it's best to just have something there before you start that shot. Now you'll see that the machine automatically weighed out my shot, I'm at 46.2 grams. My target was 45.

We've seen generally that shots will be within about a gram of target. Now, you can actually program an offset, basically telling the machine how many grams ahead of target to stop or to try to stop in order to hit its target. And then the machine is also equipped with a what La Marzocco calls drip prediction, which is mostly just a set of, like, equations to help the machine figure out, "Okay, my shot is flowing at about this rate and my target is coming up in so many seconds. So, here's how I should adjust to stop the shot and try to hit that target." It's not perfect but it is pretty close and it's about as reliable as volumetrics, in our experience. Most of the time we find volume metrics tend to be within about a gram or maybe a gram and half of our target actual liquid yield. So, overall, pretty accurate. The mass mode is probably what most people will use if they have the scales. You will probably be still checking your doses because your grinder might be off by a gram or even a few grams even if you're running a timed grinder. So, if you're checking your doses on a scale, you probably want to just let the machine handle the dosing into your cup to hit your target mass.

For brew ratio mode, however, we can actually program in a dose every time if we want to. However, that's probably not how most people will use it. Now, I have two functions for the long presses when I'm running in ratio mode. The short-dose button, if I long-press that, is my coffee dose. It will prompt me to weigh my coffee dose on the scale. My long dose, if I long-press will prompt me to tare my portafilter weight. So I'll do that right now. You just hold it for a couple of seconds and you'll see on the screen, you'll be prompted with PF for portafilter and then a zero. Now I can balance my portafilter on the scale. It will weigh and then tare, and then I'll get both of my solid red lights again. Now, I'm going to grind a dose and tamp it, and I'm not going to weigh it on my scale and instead, I'm going to weigh it on the machine itself. Again, I just need to long-press my first button. I'll be prompted with COF, for coffee. And you'll actually see that my portafilter weight is displayed here as a negative. It's basically already taken the weight of my portafilter and said, "Okay, we're going to deduct that from the total weight on the scale."

So now I have a 19.3-gram dose registered in the machine. And what's nice about brew ratio mode is that both of those weights, the weight of my portafilter and the weight of that coffee dose are stored in the machine. I do not have to weigh either again if I don't want to. So I can go ahead and I can pull another shot. And just like in mass mode, it's basically going to say, "Okay, I'm going to try to pull a target mass," except now it's calculating the mass as a ratio from the weight of coffee that it registered in the portafilter. It has 19.3 grams in the portafilter and it's going to say, "Okay, well I want a 1 to 2.2 ratio, for example, and it's going to try and target that 2.2 times 19.3 grams. The beauty of brew ratio mode is that yes, you're going to have some variable dosing from your grinder. If you want to calculate it every time you can and you can save yourself a step of grooming or trying to adjust the weight of coffee, you can just say, "Okay, whatever I get in my basket is fine. I'm going to pull a set ratio so I know that I'm going to get basically the same shot of espresso even if I get a half gram more in my basket." It will be a longer shot of espresso, have more volume, but it will be the same ratio as the standard shot that I used to dial in in the morning.

Now if I do want to change my coffee mass, again, I just have to hold down that button. So let's say you're primarily serving milk drinks like a lot of us are in cafes, you can probably just go ahead and just hit your normal dosing button. You don't have to register the weight every time, but you get that one customer that you know loves a great shot of espresso. Well, okay, now we can be a little bit more precise. I will grind and tamp as I normally would. And then before I pull his shot, I'm going to reweigh my dose on the scale. And hopefully, it's within my target range that I had dialed in the morning, but if it's not, at least, again, I'm pulling a shot that is the proper ratio that I want out of that coffee. So overall, we've got some pretty cool features on this machine.

Of course, the ABR system is not unique to the KB90, we've seen it on a few other La Marzocco machines. But the new straight-in portafilter design, the new pro-touch wands, the new steam valves and overall, the usability and features of this machine make it a really great addition for a cafe workflow. Again, it can't really be understated that saving your barista's wrists in terms of minimizing that torquing movement and making it much easier for them to do fairly repetitive tasks, you're pulling a lot of shots of espresso every day. If you can save the strain on their wrists and joints, you're going to keep them healthier and happier. And that's a really big thing. So, overall, pretty great machine. We've got really solid build quality, lots of great features to make it a really fantastic addition to your cafe. So that is the La Marzocco KB90. Thanks for watching.

Oct 17th 2019 meredithlangley

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