La Spaziale S1
Espresso Performance


Espresso Primer
First Impressions
Getting Started
Espresso Performance
Steaming Performance
La Spaziale S1 Cheat Sheet (download)

Now onto the part that sets your heart aflutter! What can this baby do?

As you may have surmised from reading Getting Started, things started a little rocky between the S1 and me. Part of this is a reflection of my own experience with E61 / HX machines and the steps for adapting to their peculiarities. Now in retrospect I recognize my expectations of how good temperature control is obtained was tainted and needed to readjust to an electronically controlled unit like the S1.

As was mentioned in Espresso Machines 101, an E61 group is too hot for brewing after being idle for 10-15 minutes and needs to be brought back to brew temperature with a cool down flush. The S1 is different. Its group will be below brew temperature after being idle (and thus needs a blank shot or two to bring it up a few degrees), or if it has produced a shot recently, near precisely the desired brew temperature. Since the group is never overheated, you need to be aware of how you can inadvertently draw down the brew temperature. For example, forgetting to draw a blank after the machine has been idle or by keeping the portafilter out of the grouphead too long. I’m guilty of the latter sin. I got away with this sloth-like morning behavior with my own espresso machine because I would intentionally let the group run a little hotter. I figured if the portafilter was a tad cool and the group a tad hot, so what? It all worked out in the wash. It’s funny how I had subconsciously adapted my preparation routine to my own sluggish predawn pace.

There’s no hope of me moving any faster in front of the grinder before 10am, so if I am to get along with the S1, another approach was necessary. Fellow enthusiast Jim Schulman suggested removing the retention clip from the portafilter so the basket would drop in and remove easily. Then I could tamp at my slumbering leisure while the portafilter remained in the grouphead. Once the basket and coffee are ready, a quick turn to remove the portafilter, drop in the basket, then back in the grouphead. The portafilter stays ultra-toasty even if I doze off for a few minutes in front of the grinder (yes, it has happened after a few consecutive all-nighters).

This same trick also works great for successive shots. I tried it with a few extra baskets. By tamping two and then starting my run, I was able to pull four shots in six minutes. Not bad for a slowpoke! The S1’s shot-to-shot performance is helped by its fast-reacting temperature sensor. After just one shot, the brew boiler’s heating element activates less than ten seconds later to bring it back to brew temperature. It’s recovered in about 40 seconds. The Amica, in comparison, doesn’t activate the heating element until the second or even third shot, resulting in the larger temperature swing of 7-8°F that I mentioned earlier, plus a longer delay once it does kick in.

Diffuser and screens

Brass diffuser, large screen, small screen
(oriented and ordered as shown above)

In the center of the S1 grouphead is a small 8mm bolt that holds the brass water diffuser and dispersion screens on. Notice that read dispersion screens, not screen. The manufacturer explains that there are two dispersion screens, a smaller one beneath a larger one, to reduce grinds passing back up through the grouphead and to prevent channeling. With the two screens in place, there is adequate room for 17-18 grams of coffee, leaving about 2mm of clearance between the top of the puck and the grouphead. You can double check the clearance is correct by locking in the portafilter and then removing it; the top of the puck will show the light impression of the grouphead bolt in the center if you have the correct clearance.

Everything drops out easily including the grouphead gasket itself, so keeping the business end of the S1 squeaky clean is easy. Cleaning the E61 grouphead is different since the dispersion screen is not meant to be removed regularly (it is wedged in the grouphead by the gasket). Instead regular water backflushes and occasional chemical backflushes with Urnex Espresso Cleaner are required.

Below are the steps for pulling your first shots, plus some added tips for the chronically lethargic morning espresso-loving crowd. Let’s assume that you’ve set the temperature to your liking (94-95°C for medium roasts and maybe two degrees higher for light roasts are good starting points) and you’ve adjusted your grinder to pull a reasonable 25-27 second espresso:

  1. Allow the group 25 minutes to warm up.

    Or leave it on* with the portafilter loosely locked in.

  2. Draw a blank shot with the portafilter in place.

    Press the two-cup button, preferably into your espresso cup to preheat it. I got into the habit of pulling two blank shots at the beginning of the day. The brew boiler recovers very quickly and my results were optimal by following this regime. If you don’t dawdle then you may be able skip the second blank shot, but it’s borderline.

  3. Measure out and grind your beans.

    Dimple indicates portafilter level is correct

    Small dimple from grouphead bolt
    and ridge are visible when there is
    about 2mm clearance

    I found that 17 grams of beans / a small heaping basket full of grinds worked great (a level basket holds around 15 grams before any settling). Smooth out the grinds to an even bed of coffee. Once tamped down, 17 grams of coffee will leave the top of the ridge for the basket retention clip exposed.

  4. Tamp firmly, about 30 pounds of pressure.

    Many people underestimate how hard they are actually pressing. If it helps, try tamping on a bathroom scale. The key point to remember is the consistency of your tamp pressure from one shot to another, not the precise pressure amount itself.

  5. Either lock in the portafilter with coffee (speedy morning people), or remove the portafilter, drop in the basket, and then relock it in (slowpokes).

    For the slowpoke approach, the basket is at room temperature but the portafilter is heavy brass and very hot. The basket and coffee will come up to temperature quickly, losing less than 2°F throughout the shot. Again this tip is mostly for slowpokes.

  6. Dump the hot water from the cup. If brew boiler light to is still flashing, wait until it is solid and then press the two-cup button.

    You may want to take a moment after the shot is complete to rinse the grouphead by loosely locking in the single-shot portafilter with its backflush disk and running another shot while slowly jiggling the portafilter handle back and forth. This “wiggle-rinse” will wash most of the loose grinds off the grouphead and dispersion screen and over the sides of the portafilter into the drip tray. Be careful not to splash yourself with hot water! At the end of a session, I also recommend a quick water backflush to clear the pathway from the grouphead to the pressure relief valve that empties into the right back corner of the drip tray. Refer to Espresso Machine Cleaning - Why, How, and When for more details on a cleaning regime that applies to the S1. 

Remember to relock the portafilter back into the grouphead to keep it warm.

(*) Hint: If you leave your machine on overnight, you can save energy by pressing the BOILER button after your last cappuccino for the day. It takes only 15 minutes to heat the steam boiler and temperature stability isn’t an issue for frothing (one of the advantages of separate boilers). Once the steam boiler is at 1.25 bar, it’s ready to go.

Dreamy espresso

Twenty-five seconds to
espresso nirvana!

If all goes well, you should see your first drops of espresso in about five seconds and continue for about another twenty. A good stream will be characterized by a dark, rich color that transitions to ribbons of dark brown / tan stripes as the pour progresses. Finally towards the end the color will lighten and the stripes stop. If the auto-dose hasn’t already ended the shot, you can press and release the button again to stop it. I noted a light impression of the dispersion screen on the puck when removing the portafilter and no signs of channeling. I suspect the channel resistance of the S1 owes to its not too deep, not too shallow basket.

One of the risks of giving an engineer precise feedback is that they’ll feel an irrational urge to tweak! Once I had figured out the coarse and fine temperature tuning, I settled into a consistent setting of 95°C for the house favorite espresso, Intelligentsia’s Black Cat. The setting never really changed more than a degree or two and much of that was my own experimentation. It’s fun to play on the edge of a blend’s “tipping point” temperature between just right, flirting with sourness, and teasing bitterness. That’s something that I accepted before as part of the serendipity of espresso-making. The S1’s impressive level of temperature control and stability allows you to pick your muse.

Touchpad temperature control also comes in handy if you like to change blends. One morning a homeroaster friend brought over some samples to try out. The first was a traditional Italian blend roasted to Full City. Temperature unchanged, the S1 pulled a 1.5 ounce ristretto with 17 seconds of tiger striping and attractive cinnamon dusting. As an espresso, it had smooth, mellow flavor, medium body, and a pleasantly edgy finish. The flavors mellowed too much and nearly faded away in a cappuccino. Next up was his “monkey” blend that gets its name from the supposedly random choice of coffee beans that go into it. The first pull was too fast. A quick tweak of the Mazzer Mini grinder 1½ notches finer and it looked great as it eeked out of the portafilter. Alas, it was narrowly sour. Using the temperature fine-tuning, I increased the temperature two degrees to 97°C and pulled two blanks to warm up the group and portafilter. One shot later all the sourness was gone to reveal an interesting, fruity blend with hints of ferment.

Yeah, La Spaziale’s on-the-fly temperature adjustment capability can be addicting.

Portafilter brew pressure gauge

Measure the pump’s output with
a portafilter brew pressure gauge

The S1’s rotary pump allows for easy adjustment however you will need an external gauge to measure its output since the S1 has no built-in pump pressure gauge. The optional portafilter pressure gauge is such a diagnostic tool. You measure the pump pressure by attaching a special adapter and gauge to your portafilter and then engaging the pump. In a few seconds, the pressure reading will stabilize. The S1 that I evaluated was tuned to the so-called Schomer standard of 8.2 bar. I’ve tried from 8.5 to 10 bar on my own machine. The biggest difference that I noticed was that pressures of nine bar and below made for an easier pull without channeling. I attribute this to the lower pressure that doesn’t force open fissures that would otherwise lead to channeling. Some espresso aficionados claim to taste a difference at various pressures. If you are inclined to tweak the pressure to discover for yourself, it is easy to do so with a rotary pump since it has a built-in bypass valve that allows you to set the pressure directly. That is, unlike vibration pumps, which put out their maximum pressure for a given resistance and rely on an expansion valve for pressure regulation, a rotary pump puts out the same pressure independent of the flow rate. In a commercial environment, one rotary pump may service several groups, plus it doesn’t require the pauses that a vibration pump must have (about one minute maximum before resting for one minute). For this reason and of course their durability and longevity, rotaries are the de rigueur in such demanding situations.

You can expect your machine to be properly regulated on arrival, so checking the pump pressure is only for diagnostic purposes or for those who wish to experiment. I was satisfied with the original setting of 8.2 bar and saw no need to change it.

Pod adapter for those on the go

Pod adapter includes narrower
diffuser and basket (optional)

One other advantage of rotary pumps is they are quieter than vibration pumps, especially when the pump is external to the machine under cabinet as is often the case in commercial setups. The S1’s is inside the unit. I don’t own a sound meter to measure precisely, but empirically it sounds much quieter and at a lower tone than the already reasonably quiet vibration pump of the Amica.

The S1 can be fitted with an optional kit for pods. This includes a narrower diffuser disk, screen, and single basket that contain the pod tightly during the extraction.  Espresso pods are popular among those who wish to simplify the preparation and eliminate almost all the cleanup.

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