While not yet offered in the US, lever espresso machine fans may have already read about the Bezzera Strega:


From Bezzera Strega - new spring lever for home use

Although it looks like a conventional single group lever machine, it's anything but. The Strega is a pour over, not a direct connect. But instead of a 3 bar boiler fill assist pump (like the pourover Pavoni Pub EL), this has an Ulka pump set at 11 bar blind pressure. The pump is activated by a microswitch that engages when the lever is at the cocked detente. When engaged, it offers water through the HX into the lever's cylinder. The pump noise quietens when the cylinder is filled and goes virtually silent when its pressurized. Lifting the lever off the detente kills the pump and starts the spring action.

It is possible to do all lever shots, by cutting to lever the moment the pump quietens. It is also possible to let the pump do the first part of the shot, or all of it, and cut to lever later into the shot. For this "Second Look", Jim Schulman looks at the Strega from every angle and usage; I'll ride shotgun, offering color commentary.

STREGA: THE MOVIE

(Hint: the videos play best in full screen; total length is about 25 minutes)

INTRODUCTORY: Bezzera has designed the Strega to be as simple to use and convenient as any semi-commercial pump machine. This includes the innovative use of an HX and group head heater to stabilize the lever temperature, and standard Ulka pump to refill the boiler and prime the lever from a standard pourover tank.





WHO SHOULD BUY IT: Despite the design tweaks to make it a semi-commercial machine, the Strega lever still requires muscular effort, it is not counter friendly, and it is slower for continuous shots than a pump machine. However the combination of a lever and nine bar pump gives a wide range of pressure profiling capabilities. This permits making brilliant espresso from coffees, including the Esmeralda Geisha, that cannot be used on pump machines.





PRESSURE PROFILING ON THE STREGA: The attraction of a lever machine is that it can be played like an instrument. The Strega's combination of lever and pump multiply these possibilities. On the Strega, the pressure of the preinfusion, the early, middle and late part of the shot can be separately controlled. This allows the Strega to emulate the operation and taste of a wide variety of high end espresso machines.



I would like to highlight that this lever/pump combo requires either an unusually fine grind or a high dose. It is better to keep the grind in the normal espresso range and add about 2 to 3 grams to the dose of normal double baskets. This will get the shots I describe in the videos. Using very fine grinds will usually get overly flat and sweet comfort food shots.

Here is some temperature and pressure info:

Shot per one Minute; no Flush:


Shot per two minutes; no flush:


Shot per two minutes, short flushes




Discussion

At a realistic 2 minute interval, no flush shot starts at around 97C and ends at around 94C. The group head heater and tiny HX make even this huge lever a near "dragon," so the two minute shot interval shows a compete recovery. Since this is about the maximum speed for making shots, the group needs to be flushed even when making back to back shots. The flushes can be kept very short, just a few seconds of actual flow (sometimes you get no flow for athe first few seconds). Longer flushes get down to a fairly stable 90C, the group head temperature. This is a good idea for very light roasts.

The machine is about as temperature stable as the Elektra or BZ07, but getting to anything more precise than hot or cold while arm wrestling a lever (as opposed to pushing a nice civilized pump switch) will be tough. However, the set up makes it almost impossible to actualy overheat or overcool the machine. It will always be in the ballpark.


Here is a video showing a leaky PF pressure gauge and the lever upswing to give an idea of the pressure ranges.


It isn't pretty, but it is clear. The pump will get up to 10 bar or so with a regular puck. The lever shows the same pressure here as blind, running 10 bar fully primed to 5 bar at the end of the stroke.

These are the maximum pressures. As the demo videos show; the idea is to retard the spring to control the flow.

This bench review is sponsored by 1st Line Equipment. There is no information as yet on price and availability.

The thread is open for public comment. Please stay on topic; irrelevant posts will be deleted to allow readers easier access to the information.

In particular, while we at HB are excited about the potential of the machine, we aren't sure about who would be interested in buying it, and for what reasons. For instance, in the current Strega thread, lever people liked the idea of a pourover lever, but were negative on a full pressure pump; mainly for aesthetic reasons. However, for my taste, it adds a great deal to the experience.

So is the machine a kluge or a stroke of genius? Can it convert lever heads? Appeal to pump people? Bezzera has certainly been unconventional here; and for that alone, they deserve some well considered comments.

ilVecchio wrote:Also, the lever with the little lady seems to be longer, better mechanical advantage.

I tried the lever on the Strega while visiting Jim, and found it difficult to operate. I'm nearly 70 and have some tendonitis in my wrists. The lever did get away from me.

Great post, Jim! I really appreciate the subtleties of making different kinds of shots.

Joel, I'll bet it wouldn't be hard extending the lever arm for someone who really wants that machine.

Roeland, it had occurred to me too that a lever machine can be elevated for better ergonomics.