The Speedster’s Preinfusion tricks
One of the great things about the Speedster espresso machine (built by Kees Van Der Westen) is the variety of preinfusion methods you as a barista can perform with it. In this day and age of exploratory work on preinfusion methods and pressure profiling, many may not know that the Speedster provides the barista with a few tricks and techniques for doing different levels of pressure profiling during a shot pull. Here’s a post to detail how the machine works with pressure and preinfusion.
Most espresso machines offer one type of pressure - the pump’s preset (or dialed in) pressure. You insert your portafilter loaded with packed coffee, flip a switch (or press a button), and the machine ramps up from no pressure to the pump’s pressure (usually 9bar, or 135psi). There is a climb from 0bar to that pressure that can take a second or two (or longer, if the machine has flow restrictors installed), but not much else.
Recently, developments by La Marzocco, Slayer and other companies have introduced programmable or manual control over pressures, which the industry calls “pressure profiling”. On La Marzocco’s new Strada machine, the barista can theoretically set any pressure at any time on the machine during a shot pull (the machine can also be preset or preprogrammed to deliver specific pressures at specific times during the shot). The Slayer works a bit differently, in that a series of flow restrictors are turned on or off as soon as you enable the shot process (the pump is always working from the moment you move the lever); this can be changed manually in between shots for different levels of pressure. Moving the paddle back and forth can “massage” the pressure between the machine’s various preset pressure points.
I am not a huge fan of these methods for two reasons.
- I don’t believe we, as “espresso professionals” (I mean the entire industry) know enough about espresso percolation and production to take advantage of these kinds of precise pressure adjustments to improve coffee
- Personally, I have not tasted any real improvement (or detriment) in taste from shots I’ve had on both Slayers and Stradas to justify the money and expense put into this technology.
That said, even though these are developments in the last 12-18 months, there is another machine that has been on the market since 2008 that does also offer some control over pressure profiling, but in a much more manual (and imo, less prone to break down) way: the Speedster.
The Speedster’s pressure delivery system
With the Speedster, I’m able to pull a shot with the following pressures:
- Neutral (gravity fed, not much else) preinfusion pressure, up to 7 seconds or longer (set time, not adjustable longer, but can be adjusted shorter, see below)
- Ramp up to line pressure, controlled by flow restrictors (usually less than 1 second, not adjustable)
- 3bar (or line pressure from your home or office’s normal tap water pressure) for as long as you want
- Ramp up to pump pressure, controlled by flow restrictors (usually about 1-1.5seconds, not adjustable)
- Pump pressure, whatever the rotary pump is set for - for as long as you want.
- Ramp down to line pressure (slower than ramp up, not adjustable)
- Line pressure finishing at 3bar / whatever your line pressure is (again, for as long as you want)
The Speedster achieves these things via two rather unique design elements on the machine: a two stage (or two gear) water and pump actuator control (the brewing gear lever), and a separate preinfusion chamber that in some ways mimics the preinfusion chamber on lever espresso machines.
The beauty of this system is that you as the barista can control 1, 3, 5, and 7 for as long or as short as you want. If you want to have a very short preinfusion with near-neutral water pressure, you can have it by dropping the machine into “second gear” faster or immediately (by passing 1st gear entirely). If you want an extra long 3bar preinfusion, you can do this too by leaving the machine in 1st gear for a longer period. You can also control what I call “post infusion” (probably a bad term) by dropping the machine back down to first gear after brewing with the pump for a 15 or 20 second time period.
You can even get more complex in your brewing method on the Speedster. For example, you can start the shot in first gear, pop up to second quickly to rapidly fill the preinfusion chamber (thus shortening the initial low-pressure preinfusion, forcing the machine to get up to 3bar preinfusion quicker), then drop back down to first gear to continue preinfusing at 3bar… and eventually, pop up to second gear again to get the pump working and brew the shot at 9bar.
How this improves espresso, I still don’t know. As I said above, we still don’t know jack about espresso extraction as an industry, and I’m very much in line with the industry in my own knowledge. I still experiment every day with espresso on the Speedster, and have found most of my shots benefit from the following brewing method:
- Preinfuse at near-neutral pressure for full time the machine allows (as long as the preinfusion chamber is still filling up and the piston is still extending from the machine’s front panel, the puck is getting less than 1bar pressure) - about 7 seconds
- Continue preinfusion with 3 bar line pressure (still in 1st gear) as initial dribbles of brew come out of the portafilter for about 3 seconds
- Pop to second gear, brew for around 20 seconds
- Drop back down to first gear, allow machine to ramp back down to 3bar pressure, finish off the shot (about 5 seconds)
- Drop the machine back down to off or zero gear to finish shot.