*somewhat OT, but I'm glad to see the Strega finally available and shipping...
I get the feeling that Cremina prices (new & used) will come down to a more realistic range again.

Since Jim's review is largely complete, I took the liberty of splitting follow-on discussion from recent owners to Owner experience with Bezzera Strega. If members have a question/comment specific to this review, reply here, otherwise reply to the new owner's thread or start another more specific Strega thread. Thanks.

It would be too much coding for it to appear in both groups, being a bit of a hybrid...

I was thinking of the Strega's broader appeal to those who like levers and pump-driven espresso machines, so I split the thread to the Espresso Machines forum. Nothing more to it than that.

Hi Mitch,

I haven't done any extraction experiments. It's fairly clear that the extraction on the Strega is even more front-loaded than on other machines, since the preinfusion is long and at high pressure. However, despite the front loading, there is a very clear taste difference between different ways of running the lever later in the shot.

Of all the possible ways one could vary the shot on this style of machine, I only vary one parameter, the flow rate. I let the pump preinfuse until there's flow, then I cut the pump off. The compressed air then creates a flow that is initially strong, but tails off. I let it tail to the rate I want, then I let the lever up and retard to to stay at that rate. In other words, I only do steady flow shots; but some at a steady slower flow, so they take about 20 to 25 seconds to go from pump cut off to end, and some at a steady faster flow that only run 10 to 15 seconds.

If I want a shot that tastes like a dessert wine, i.e, the perfect Peppina/Microcasa shot; I run a slow flow/long time shot. If I want something more creamy and toasty, I do a fast flow/short time shot. These are closer to classic pump shots, but with the lack of bitterness one gets from commercial levers.

I'm pretty sure the difference between these two styles of shot is not in extraction, but in how the fats emulsify and modify the mouthfeel. The longer, lower pressure shots are less creamy, but if you let them cool, they would probably taste the same as the shorter, higher pressure shots.

The big news in terms of extraction is that there is no excuse for ultra-bitter shots from any machine. This super-bitterness comes from cooking and hydrolizing the coffee, so that the long chains molecules break down and get into the cup. This is not the good high extraction that gets the slower dissolving caramels into the cup, but the bad over extraction that breaks down the cellulose chains that should be insoluble and left for the termites.

The bad extraction happens when there's excessive heat, pressure and acidity. Clearly a spring lever is less prone to this, since the pressure diminishes and the temperature of the water stored in the group drops; but it is possible when doing an overly ristretto shot on a pump machine, especially an HX that heats up as the flow slows down. The Strega's immunity to overextraction gives a lot more leeway for doing pressure profiling without screwing the pooch.

I guess that if you added a rotary pump to any commercial multi-group lever/HX machine to get high pressure preinfusion, or added a gear pump to a double boiler machine to get the pressure to ramp up, and then ramp down again, you could achieve roughly the same effects.