another_jim wrote:The home spring levers don't develop 10 bar pressure, and holding a consistent pressure on a manual is harder (at least for me). The pump preinfusion allows one to pressurize anywhere from 0 to 9 bar prior to having any flow.
After watching Jim's demo, I wondered whether someone without a Strega but with a hefty spring lever or even a manual lever can ramp up pre-infusion pressure. I came across this by Doug Garrott in the original Strega thread, have tried his method on my Microcimbali and am getting nice ristrettos.
orphanespresso wrote:... I have been grinding in such a way as to not get any drips of espresso on preinfusion and pulling the lever down 1, 2, 3 or as many times as it takes to get the lever to be as low as possible on the stroke thinking that this will maximize the pressure on the puck...with each pull a bit more water is gulped into the cylinder and massaged into the puck at ever increasing pressure, but obviously a non linear pressure profile due to all the pulls...more of a stair step profile if done on a graph. I get the sense of extracting the 5's, 7's and 9's and then of course the reverse on the downpressure side of piston travel. And the heart of the crema arrives much later than the first parts of the pull.
orphanespresso wrote:... as an old school type ... the wheel seems to be not quite reinvented here, just a bit tweaked.
In that light, I wonder if a commercial lever with its full-strength spring can also be coaxed to make "impossible espressos" like the Panama Esmeralda Geisha? (And thanks, Jim, for demonstrating how to slow down the lever pull.) The ramp up using Doug's step method is obviously not as smooth as with a vibe pump, but with careful application, it may work. Or am I missing the something
that's not there for pre-infusion pressure in a traditional commercial lever?
Other related musings: Are major Strega advantages its consistency/repeatability and the way these allow one to trust playing its variations like with a fine musical instrument? The Strega is obviously a home machine with the pour-over tank and single group. In a commercial environment where a single coffee is usually dialed in for that day, would one need its easy and repeatable variability to prepare challenging coffees?