Gabriele Cortopassi, one of the curators of the Italian Coffee Blog "Il Caffè Espresso Italiano" took the opportunity to interview an Izzo representative at Milano Host: http://www.ilcaffeespressoitaliano.com/ ... na-a-leva/

While I found the interview interesting I found some of Izzo's responses and explanations of how levers work a bit odd..

Here is my translation of the interview:

Gabriele: Izzo, as a leading company regarding lever machines, can you explain to us how they work?

Izzo: Our company pays a lot of heed to "tradition", and seeks to bring to the rest of the world a system of traditional quality, such as a lever machine, defined by "coffee gurus" as "the press" in that it succeeds in producing a complete extraction of the coffee blend. Our lever machine is completely mechanical with a bit of modern technology that only serves to aid the mechanics. We also produce other machines, semi-autos, full-autos, etc.

G: How much has the technology changed with respect the the lever machines from the 50's?

Izzo: The system is pretty much the same; our group, which by simply looking at it can seem pretty simple in reality is composed of 38 small separate elements, elements that in time underwent an evolution that today allows us to produce with these machines the best extractions and shifts the importance [from the machine] to the operator and the cup that they serve.

G: How does a lever machine work exactly? In a pump machine we have a preinfusion, then the pump activates to push water across the coffee puck at 9bar, a lever machine I suppose would operate in a much different manner. Can you give us a bit of a technical description?

Izzo: Very different, and this is why the lever is my machine of choice! First of all a lever machine feeds its water directly from the boiler therefore we aren't talking about some stagnant water and from every group there is a direct flow right to the puck [from the boiler], the causes the extraction to behave completely differently with respect to an automatic or semi-automatic machine.

G: Therefore in practice when we pull down the lever water starts flowing directly [to the coffee]

Izzo: As I lower the lever hot water enters the group and starts infusing at a hot 128 C.

G: Wow, and this water hits the coffee, therefore the extraction temperature is extremely high compared to the classic pump machine.

Izzo: Yes, for us the product needs to be cooked, not simply warmed, so when I lower the lever and I preinfuse for 3 to 5 seconds, then I lift the lever and give 14bar pressure to the coffee with a diminishing pressure curve to finally arrive at 0bar, this is very different compared to a straight 9bar linear pressure applied from automatic and semi-automatic machines; and I'm going to extract all of the noble fats and more volatile aromas.

G: This is helpful for extracting less bitters, in other words you are extracting less at the end of the extraction during which the "undesirable notes" are usually extracted.

Izzo: Exactly!

G: We know that cleaning and maintenance on a lever machine is different than that of a pump machine...

Izzo: The lever machine is self cleaning in that all the water in the group at the end of the extraction exits, and only exits through the group.

G: There is no solenoid valve...

Izzo: And therefore we don't need to flush with a blind basket: meaning we don't have dead time or someone whose time is tied up in machine maintenance, you only have to worry about cleaning the portafilters correctly. The machine never has to turn off and in the morning we don't have to throw away the first coffees made, just a flush is needed to get the group up to temp.

G: For a good portion of the clientele, these machines have a certain fascination, not just in Southern Italy.

Izzo: We'll just that that there is a bit of a resurgence, thanks in part to a restyling that has smudged up a bit the rectangular shapes of the old lever machines, with a machine that is now made completely by hand and customizable. these machines are in high demand in foreign markets as well.

G: Therefore you do a lot of exporting of your products?

Izzo, Yes, in Asia, in America...

G: With respect to the ability to control parameters, preinfusion time, temperature, temp stability, how does a machine like this stand up?

Izzo: A machine of this type has more stability, because I don't have a double boiler and I don't have to deal with preinfusion through a heat exchanger.

G: Therefore: Its simplicity is its perfection.

Izzo: That's exactly what we try to transmit to our end consumers, it is they who must decide what is best way to prepare an espresso.

Thanks for sharing this, it does seem a bit odd. I know that some favor the home open boiler levers because temperature control is so much easier and there's little chance of cooking the coffee, I put a PID on my La Peppina and experimented across temperatures and lowering the temps from boiling definitely worked for me. It also seems to go against small levers like the La Pavoni that make good shots for the first two or three shots but then must be cooled to avoid burning the coffee. Maybe I'm missing something here, though.

Agreed, the only thing I can think of is that he was in "marketing hype" mode and speaking only in the context of the Izzo lever.

I love my Izzo Leva, but this seems to be more hype and double talk than anything else. They don't use a double boiler, so they instead claim that their version is more temp stable. Even with a PID like on mine, I'd find that a bit hard to believe.

And I don't think I could get 260 water at the group if I tried at the hottest settings. I don't even have the boiler that hot, so how is it going to stay that hot thru 15 pounds of brass radiating heat away?

This guy answering the questions is likely more of the marketing side of the business. I'm sure most of the very knowledgeable engineers of these old designs are long since dead or retired. I'd rather take input from someone like Salvatore here in Solvang, he's been at it for a good half century now.

Thanks for sharing it was an interesting read. As an engineer/scientist it concerns me when someone only advocates the good and cannot appreciate the inherent limitations of a design.

I like levers for as many reasons they are impractical as they are practical

Little of it made sense, but certainly a declining pressure or flow profile is an importance difference from most non-lever machines.

Three things really bothered me about this person's description:

First, s/he [gender of Izzo representative not specified, so I will say 'he' for convenience] claims that a dipper is better than a plumb line because boiler water is not "stagnant".

Then, hitting the puck with superheated water (which I doubt is actually that hot by the time it gets to the group) is apparently a good thing.

Then that the spring's pressure curve goes from 14 bar (really?!?) to 0. Yes it will wind up at zero eventually but the shot is pulled out from under the stream well before that.

Lesser things that bothered me are his claim that levers are gaining resurgence because of their clever body redesign, I am the first to state that I dislike the "steel box with grouphead" but simply changing machine aesthetics is not going to cause a resurgence in a vintage operating mechanism.

Also this ritual of pulling and dumping the first two shots of the day before the machine is ready to serve customers: I was always under the impression that this was simply the equivalent of flushing the group up to temp while also making sure any of yesterday's old coffee was out of the doser. Claiming that levers simply need a flush to me is silly, you are just promoting the possibility that the barista serves a client or two day old ground coffee. Clients know better too, I've heard people who walk in to a shop that's just opened for the day ask how many shots the barista has pulled, they want to make sure their coffee isn't going to be made with stale grounds.

I'm sure they mean well but they don't do much of a service to Izzo or lever machines in general here. Hopefully just lost in translation? 128C probably refers to boiler temperature?

MCALheaven wrote:Hopefully just lost in translation?

Definitely not lost in translation, I translated this myself. All the seemingly ridiculous things he said, he actually said.

Hmmm