Using a lever machine

lever-texture

These last few days have been a pleasant, but steep learning curve.  I know I’ve muttered about pressure profiling from time to time, but I hadn’t really played with a lever machine properly until Gwilym’s WBC prize arrived.  1
I am not quite at the popeye arms stage yet, but I could see how you could incorporate a machine like this into a serious workout routine.  I have had some delicious shots, but I have had to abandon the traditional time frames I have used for espressos I know well.

Lots of little things make an impact.  The size of basket has a very strange impact – keep the dose the same, but have a bigger basket means that more water fills the chamber above the coffee meaning you will pull a longer shot.  Changing basket but keeping the dose the same has enough of a weird impact using my Cyncra, but this one single variable has a terrifying domino effect on the shot!

Gwilym came by today, he’s on his way to Italy to visit La Marzocco and wanted to pick up some coffee to play with.  We thought it would be fun to pull some shots of the same batch on the Athena that he’ll play with out there.  The impact of even tiny adjustments to pre-infusion time made an astonishing difference to the cup.

As you can see from the photo above I dug out my Gaggia naked portafilter, as I was curious to see what effect the lack of dispersion screw would have.  (This is the first machine I’ve used without one).  Turns out it is nothing noticeable, but then I am not sure how much detail can really, really be discerned from a naked portafilter.  They do still look pretty though.

Shot times appear to have gone out of the window.  Or at least the window has moved quite substantially.  People who go to Naples often seem to come back remarking on the 45 second shot time.  I haven’t had much under 35s that I’ve really liked, though I haven’t played much yet with barely any infusion so that may change things.  2

Now I’ve never been one to worship at the altar of crema, I don’t want more of the stuff, I don’t read too much into its texture or its colour.  However from an aesthetic point of view the shots from the Athena do look remarkable pretty.  Darker espresso roasts than ours mottle/tiger stripe in a wondrous manner (had some very tasty shots of Espresso Rustico from Counter Culture which I wished I had photographed because I think they’d be an interesting reference point for barista competition judging).

I can’t quite put my finger on exactly how the shots change.  I also admit that I’ve had more experience than most with pressure profiling, and the impact of soaks and ramps.  I do know that you can get some very interesting textural and taste based results (I am separating taste from flavour here), but I also know what a knife edge it can be.  I’d love to pull a few hundreds shots on one of these and see how you build a workflow around them, would it lull you into a pleasant and soothing rhythm or taunt you with its crawling pace.  Plus if you pull a choker then there isn’t much you can do except be patient.  3

I consider myself very lucky that Gwilym has kindly let us play with it.  If you are coming to roastery any time soon then I’ll probably try and force a shot or two onto you and talk in an overexcited way.  I am aware this post comes off the back of a post about how silly espresso is, and how we should all love brewed coffee, but from a personal point of view it is rare that I get the opportunity to go through a learning experience like this one.

I’ll try and post more about it all as I learn a bit more and have something solid and interesting to say.  If you have experience with lever machines then I’d love to know your thoughts.  If I have one gripe with the machine (and this is exceptionally churlish, considering I am borrowing a friend’s prize) it is that the cup tray is really quite tiny.  Petty?  Me?  No….

  1. Yes, we kindly offered to ‘look after’ it for him for now…  ↩︎
  2. For the record I would start the time the moment the lever is sufficiently pulled down that you can hear the water entering the brew chamber.  Other than that it is noticeable how eerily quiet the whole process is.  ↩︎
  3. I have been told a couple of methods to interupt the brew, but frankly they either scare me or increase the likelihood of me making a mess of my clothes and I just can’t condone those things.  ↩︎

18 Comments

  1. Nice post James! What a good thing it is to get back to some of the roots of espresso – and be reminded of how much technology has changed ‘spro…

  2. I totally agree with the notion of abandoning all pre-conceived thoughts or “rules” for espresso when dealing with a lever piston machine.
    When we first got our Z9 lever I really wasn’t expecting much in terms of pulling a decent shot (direct boiler, no saturation at the group head etc), it was more about the aesthetics than anything else. However after playing around a bit it now pulls the most amazing shot!
    The pressure-stat (mercury switch) is set really low so the thing is useless for milk, but after letting it heat up for around an hour it’s all good to go. At the moment we’re running it single spout with synesso triple (24g) baskets. 8-10second pre-infusion and cutting the shot normally (usually take around 35seconds incl pre-infusion).
    The result is the thickest “espresso” you’ve ever seen. You literally chew your way through it the whole way. Now normally I’m not big on massive body, and far more excited by clean and interesting flavours, but this thing is incredible!
    The flavour profile is not (like you would expect) ristretto-esque either, though definitely not like a standard espresso either.
    I should also mention that the temps @ the head are wild too, beginning at 97C and dropping to 88C by the end of the shot.
    It still boggles me every time I pull a shot through it but damn it tastes good.

  3. We use our 1964 Boema dual lever group machine in our cafe every day. I find it far more relaxing to use with big sweeping movements and thick rich pours. I find that a 8-10 second preinfusion (with the lever in the down state) is essential for generating a full, crema rich shot. Anything less will cause weak crema that breaks apart (regardless of the grind). We had the boiler temp reduced to prevent scaulding from the direct path from the boiler to the group. Our staff love using it. It can be very forgiving of grind and dosing errors as you can compensate by pushing or holding back the lever, very helpful when you are working in an outdoor environment and with staff of varying skill levels.

  4. hey James, thats funny i have just finished modifying a San Marco lever arm, saturated boiler PID etc and its my new favorite machine, really changes the character of the shots it pulls, big and really sweet. The silence as the shot pours is the best. We put a gauge on the portafilter and the pressure curve is interesting! Not too sure how the pressure and the temp make it that different but all the staff actually come upstairs and make a coffee on it rather than the machine we have in the cupping lab!

  5. The flavour profile is not (like you would expect) ristretto-esque either, though definitely not like a standard espresso either.

  6. Hey while Gwilym’s in the land of Enzo’s birthplace, see if he can snag me something to keep Enzo afloat just a little bit longer (ya know, boilers, computer bits etc.) THANKS!!!!

  7. you actually *have* used a machine without a dispersion screw before. ;)

    the overwhelming difference i experience using various kinds of piston levers is this: they seem to “expand” single origin espressos, teasing out a much more entertaining range of traits. i’ve always assumed this was a function of declining pressure. i have no proof of this.

  8. A nice article, but does only just scratch the surface of the difference with levers.

    I’ve owned a Elektra Microcasa a leva for ten months at home. What’s interesting is the ‘relationship’ you build – with an inanimate object. All the noises, all the times to do things are subtly different and aren’t based on the flow rate from the pump (it took me a while to understand that).

    What has been eye opening is what you get from lever is subtly different, perhaps the way in which the water is pushed through performs extraction differently. Whatever happens I can tell the difference too between a machine and a lever from the taste. The taste isn’t quite as intense, has a more open pallet and although you do get crema, it doesn’t over power the other tastes.

  9. wow interesting article. right now im working on a lever maschine too (before cyncra.. ).

    with the more than 1000 shots i’ve made, it changed my opinion about espressomaschines in many ways.
    i truely underestimated the power of preinfusion. when i have the feeling the shot will be too slow, i extend the preinfusion phase. it seems that the prebrewing in the filter reduces the shot time for a balance between sour and bitter. shot times over 25 secs would kill every espresso on this la san marco leva (3 groups). maybe it’s the fault of the beans (martella mirius – way too old!).

    i agree that the filling height in the portafilter much more flexible which is a benefit for all the lungo/coffee drinkers.

    my 2 cents for the flavour profile: temp is rising with shot time.

    greets form berlin

  10. I’ve found that it provided more acidic for the light roast while with the darker roast ,the shot was smoother and less bitter than the the shot from regular pump machine.

    in my opinion, the lever machine is very good for the darker espresso roast.

  11. These machine are looking very effective. It will really prove profitable to improve your espresso. Nice post. Thanks for providing it.

  12. BZ we are finding the same thing, as our machine has a precise temperature setting we can fiddle with I am also assuming it is the pressure curve. But SO coffee tastes real good. We also use 18gms in a 21gm basket to avoid the bottom of the piston chamber fouling the top of the puck.

  13. Shot times over 25 secs would kill every espresso on this la san marco leva (3 groups). maybe it’s the fault of the beans (martella mirius – way too old!).

  14. Wow what a great article i am really impressed.. Just found this blog today and love the information on it, will be bookmarking it :)

  15. There’re 2 important things about pulling espresso . One is “temperature” ( everybody knows it ),the other is “pressure” .
    About the “pressure” , I’m not talking about 8 bar or 9 bar pressure . What I want to emphasize is the “vibration” of the brewing pressure .
    Whether vibe or rotary pumps , they all produce vibrations during brewing espresso. Because water is not compressible , the vibration will go through the pipe ,from pump to the grouphead when you push the brew button . The volume of vibrations influence the taste of your espresso and how the crema looks . That’s why rotary pumps are better then vibe pumps when used in espresso machines.
    Back to the lever machine , when the spring producing the 9 bar pressure , there’s no vibration at all.
    So you can pull your espresso in a very smooth pressure . Not about the pressure curve (many barista think it is , but I don’t), the stabilization of the pressure is the key point.
    But the temperature is a big problem for lever machine cause the lever machines use the HX boiler .
    If you can PID a lever machine ( then you can never use it to steam milk again) to solve the temperature problem , you can use the lever one to beat any fancy machine like synesso or the others very easily.
    In fact , I tried couple of years ago , and I have an air driven espresso machine . That’s another story ——
    http://www.home-barista.com/espresso-machines/time-to-retire-vibe-and-rotary-pumps-t111.html

Submit a comment