bostonbuzz wrote:1. For purposes of home use, I'm wondering if I can pull a shot that will expose as many flavors out of a coffee with a commercial lever as I got from that perfect strada shot. I'm convinced that straight pressure cannot do this given my years of use of a HX and double boiler E-61 machine.

2. If god shots are possible, which machine can give the greatest ratio of attempted shots to god shots, commercial levers, or profiling pumps? Thanks for your informed answers. Please don't take anything above to be incendiary, I did not mean it to be, and I don't want to talk much about quality problems inherent with all cafes.

3. Assuming 1= yes, 2= maybe, we should organize a shoot-off somewhere. I don't recall any shot-to-shot comparisons of dialed in commercial levers and profiling pumps. I'm thinking levers (strega, L1, more commercial) and pumps (strada, slayer, etc.).

I know what you mean about the richness and flavor separation in a state-of-the-art pressure profiling pump machine. But so much has to do with barista skills. My local coffee bar only excels to the level you describe when their most skilled barista is pulling shots. Other shots with the same coffee and machine are like the typical third wave experience you described.

My first guess is the Strega is as capable as a pressure profiling pump machine because of its hybrid pump and lever combination, while machines like the Strada and Slayer optimize that capability for a high traffic environment. A commercial lever where you can assist the lever may be similarly capable.

I've gotten stunning shots out of the Conti Prestina but rarely use it for one coffee that's dialed day after day. You can assist the lever on the Prestina and some others. You can retard the lever on any such machine. The Prestina gets more flavor separation than my home levers, including the Cremina. What would cause this difference? Is greater flavor separation than a home lever because of the wider, flatter coffee cake? My Isomac Amica E61 group machine created consistent delicious shots but flavors were more merged than with the Prestina. Both have a 58 mm group but the E61 group has a thermosyphon to heat it.

I'd be interested in comparing the Prestina to a Strega to learn if the Strega's high pressure pumped preinfusion can be imitated by pushing the lever. Some coffees benefit from high initial pressure, others are softened nicely by lower starting pressure than most pump machines. For other coffees softness can be at the expense of delineating some flavors. Here is where pushing the lever could help or where a commercial lever with a stronger spring than the Prestina would be ideal. Also declining pressure of a spring lever tends to minimize overextraction.

Added: My incorrect speculation is lined out after Jean-Pierre caught the error.

Another issue may be temperature range and whether the temperature climbs or declines during the shot. The Prestina's signature shot has a fairly large temperature decline from start to finish, but I've never used it for enough back-to-back shots to heat that 18 lb. group for smaller temperature variation. I expect those high end pump machines have group temperature that's closer to the boiler water temperature, but I may be wrong.

I also wonder if the Prestina's advantage over home levers may be due to the temperature decline during the shot compared to temperature rise in a home lever? Higher start temperatures may extract the brighter and floral flavor notes first. (Not! My error is considering the temperature measurement outside the group.)

Applying barista skills to a particular coffee would be critical to optimize variables of temperature, pressure, flow rate, and extraction ratio.

The question I would add is whether there's much difference between a commercial lever and a high end pump machine with a skilled barista optimizing each.

Good catch. I was pondering that late at night while thinking about the measurements I see on the outside of a home lever group. I'll correct myself. The temperature drop during the pull may be smaller on a home lever because the less massive group heats faster. You might also would have a narrower temperature range throughout the pull unless you cool the group or portafilter between shots.

In the commercial lever temperature thread some machines showed less temperature drop than the Prestina.

The temperature profile of a commercial lever group