La Spaziale S1
Steaming Performance


Contents

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

This is one area where comparison is almost unfair: The S1 absolutely rocks the house in the steaming department! This comes as no surprise, since it has a 2.5 liter boiler and 1250W heating element dedicated to steam production. Our other comparison machines, the Rituale with its 1.4 liter boiler and 1400W heating element and the Amica with its 0.8 liter boiler and 1400W heating element, are capable but clearly outgunned by the S1. I’m reminded of the scene from the movie “Jaws” where Sheriff Brody (played by Roy Scheider) first sees the Great White and says in a slacken-jaw, deadpan voice, “You’re gonna need a bigger boat!”  That’s how you’ll feel if you approach the S1 with a twelve-ounce pitcher.

Big steaming pitcher

S1 has a huge steam
reserve—twenty ounce
pitcher recommended

So what does all this steaming power buy you besides the ability to boil milk in less than a minute? Before answering, please allow for a short review of what’s happening when you’re frothing milk (for one of the best-written articles on the subject, see The Milk Frothing Guide by Aaron De Lazzer).

Frothing requires high-velocity dry steam to introduce air into the milk. These teeny-tiny bubbles are called “microfoam” and give the rich flavor and texture sensation to milk that we adore. The smoothness that delights the tongue is analogous to the same sensation we experience when eating ice cream. As we all know, there’s little pleasure in trying to eat a solid block of frozen cream. First you must add some sugar, whip in some air (about 15% for premium ice cream and as much as 50% for frozen custard), and voilà, America’s favorite frozen treat. Making the smoothest, creamiest lattes and cappuccinos is about a similar result but by way of a different process. Simply stated, it requires introducing air forcefully and without too much water into cold milk.

Why does it matter if too much water is introduced along with the steam? A little water won’t dilute the flavor noticeably for larger quantities of milk but it does drive up the temperature more quickly than drier steam would. Speeding up the rise in temperature with hot water leaves you less time for the first phase of frothing called “stretching.” The milk accepts air more readily when it is cooler. Depending on the desired microfoam texture, the stretching phase continues anywhere from 80 to 110°F after which the last phase of heating, called “texturing,” finishes the process by raising the milk to its final temperature of around 150°F. The texturing phase requires creating a vortex with the steam jet to help break any larger bubbles that may have inadvertently formed. Nobody wants to have soap bubble-sized foam in their milk, it tastes dry and airy. Bleech!

The table below summarizes the performance of these three machines heating water from 40 to 160°F. These numbers are all using the respective stock steam tips.

8 ounces

10 ounces

12 ounces

16 ounces

Seconds

Final Volume

Seconds

Final Volume

Seconds

Final Volume

Seconds

Final Volume

S1

20

9.0

33

11.2

39

13.5

67

17.8

Rituale

61

9.0

75

11.3

84

13.6

114

18.0

Amica

38

9.0

53

11.2

63

13.4

80

18.0

The S1’s steam tip works ideally with six ounces of milk or more. It has three large holes that create a “standing wave” of turbulence. Because of its wide dispersion pattern, the stock tip doesn’t lend itself to swirling—you’ll instead hit the milk dead-center about ½” below the surface and let it rip for about 15 seconds until the temperature reaches 100°F or so, and then plunge deeper until the temperature reaches 150°F.  If you have previous experience with other lesser capacity machines, expect to spend some time relearning your old techniques, since the increased volume and speed don’t give you much time for finessing the development of microfoam. With only a little practice, I was able to steam great microfoam for single servings; as the table above suggests, it only requires 10 seconds or so of stretching followed by a mere five seconds of spinning for such small quantities. You will need to focus to avoid overheating the milk or creating too much foam. You may start out by practicing with water and observing the turbulence patterns, learning to alternate between the dead-center position for the standing wave when stretching and the close-to-the-side position when spinning.

Lots of forceful steam is the key. The two Isomac machines are best with steam tips that are appropriate to their capacity. For example, the stock Isomac tip has two tiny holes that allow the Rituale to steam continuously at 1.1 bar since the heating element can replenish steam as quickly as it escapes. The S1’s behavior is different—it has a huge reserve that supplies a large volume of steam although not necessarily at as high a continuous pressure.

This difference revealed itself in an interesting way. I assumed that its huge boiler would work fabulously. And it does, especially when the pressure is highest. Unlike the Rituale that activates the boiler with a mere 0.2 bar drop in pressure, the S1 is programmed to turn the boiler on at 0.8 and off at 1.25 bar. The S1’s tip seems to work reasonably well with respect to speed anywhere in this range since the volume of steam is so great that a slight drop in velocity is hardly noticeable. However, I noticed the quality of the microfoam faded at the bottom of the S1’s steam boiler range. While I never bothered to glance at the steam boiler pressure gauge when using the Rituale, I would check it before I started steaming with the S1 to verify the pressure was at least 1.0 bar and wait the additional 20-30 seconds, if necessary.

Frankly, the above comment is quibbling. Yet it’s only fair to point out a weakness in an otherwise obviously superior steamer. The underlying reason is that the S1’s steam boiler relies on a temperature sensor instead of a pressurestat. Draining water from the tap will quickly get the attention of the boiler’s temperature sensor, but the escape of a little steam doesn’t affect the sensor reading enough to assure the heating element will activate momentarily as it would for the Rituale. The designers could improve an already impressive performance by either relocating the sensor closer to the water inlet (the sensor is currently on top of the boiler and water enters near the bottom), or better yet, take advantage of that fancy processor to automatically activate the heating element whenever water or steam is drawn until the pressure reaches the maximum again.

Smart ergonomics are responsible for a lot of that elusive “je ne sais pas quoi” which separates the mundane from the extraordinary. The S1 scores well with its large steam knob that sports a rubber grip and quick, crisp closure. Two fingers can snap it shut easily and the ¾ turn from off to full throttle leaves plenty of margin for finessing the steam output. This comes in handy when you want to steam with smaller amounts without accidentally painting the kitchen walls with milk. The Isomacs and especially the Rituale don’t have the same range as the S1, so this observation is less important since you will more than likely adopt a binary full on or full off steaming routine in their case. The S1 steam arm mates evenly with the tip, that is, there is no “ridge” between the wand and the screw-on tip, so it wipes perfectly clean every time. Cleaning the Isomac wands requires more attention since the ridge between the wand and tip tends to trap baked-on milk.

The Isomac L-shaped steam arms move laterally in an arc. They reach the drip tray in the downward position, so purging the wand of condensed water is easy. It is equally easy for your fingers to slip off the tiny grab tab and burn yourself, so I chose to leave the arm parallel to the countertop and maneuver an empty pitcher underneath it instead to purge condensed water.

The S1 steam arm, in distinct contrast, moves freely on a swivel joint. With the S-curve shape of the steam arm, it reaches to the bottom of the largest pitcher without difficultly and tucks away to the back of the drip tray when not in use. A fair amount of condensed water is trapped in the curve between uses, so remember to purge the wand extra long (a good five-second blast). The wand gets very hot and enough of the heat conducts through the rubber grab to remind you to be careful. A plastic grab tab doesn’t heat up, but on the other hand, they tend to slide around, so the rubber grab seems to be a more practical solution. Finally, the S1 has enough steaming power for a 32-ounce pitcher, but I found that the steam wand length and boiler capacity work best with a 20-ounce pitcher.

Water Tap Performance

The S1’s large boiler shows off again in this run-off. The flow rate is considerably higher than the Rituale, topping eight ounces in 10 seconds at 203°F. Americano lovers will be thrilled. Even those who wish to make instant soup or tea won’t have to worry about draining the boiler down too quickly. The water tap is fixed over the drip tray, so it’s easy to quickly rinse the portafilter. Do pay attention when you first use it—the flow is much faster than prosumer machines and it does sputter a little. Sometimes I like to add a half-ounce of water to an espresso that wasn’t “just so” to smooth out the flavors. That’s tricky with this water tap because of the high flow rate as well as the reaction time of the electronic button. Pressing and releasing the button starts the flow and a second press / release stops it, so you have to be very fast if you want only one ounce.

Below are the water temperatures for each machine. Note that the Amica doesn’t have a dedicated water tap; it uses the steam wand instead. It splatters quite a bit and I mildly scalded myself even though I had been warned. I recommend using either a large cup or high-sided pitcher for delivering hot water from the Amica.

6 ounces

8 ounces

Seconds

Temperature

Seconds

Temperature

S1

7

203

10

203

Rituale

11

202

15

198

Amica

16

202

19

202

I normally wouldn’t include the “Seconds” column but given the high flow rate of the S1, it’s worth noting. I acclimated to the S1’s waterfall-like tap performance after a week and no longer consider it too fast. It is curious how one’s perceptions change in short order.

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