5 bar wonder - why does it taste good???

[Kristi]

A wrong pump installed in a machine has left me temporarily (till this afternoon) with a Bric that only puts out 5 bar at the group.

I grind the beans the same settings I used for Eliane (which was set for 9 bar but kept drifting to 10).

The liquid starts dribbling out at 5 secs as opposed to 10-15 sec on the Eliane. This is illogical.

I let it run for 25 sec or so and don't get quite as much crema as I did with the Eliane. This makes sense.

BUT IT TASTES GOOD. It starts the pour faster (illogical), it does not pour with as much gusto (logical), I do not get as much crema (logical).

Thinking about it it's amazing that it is even remotely drinkable, but tastes like a good though slightly thin espresso/latte.

Maybe....... because of the low pressure the preinfusion is not tamping down the granuals as much as they would in a 9 bar head??? By the way, preinfusion is a real thing on this machine - put lever half way up (45 degree position up from straight down), water will gently spurt out a bit, then pause, then spurt out again, then pause, repeat.

Knowing this, I would go crazy (read certifiably insane) if I had a Pavoni type lever (which I had brief use of 10 years ago) because you can vary the pressure all over the place, dynamically. Too much for my little mind.
Kristi

[another_jim]

It's probably the same effect as with lever machines, where it's been noticed many times.

My overall guess is that pressure acts like the "loudness" button on a hi-fi; it boosts the high/bright, low'bitter flavors at the expense of the subtle middle flavors. So lower pressure reduces body and crema, but can improve the taste.

The puck is less compressed at 5 bar than 9, so the coffee percolates through more quickly; however, once the puck is stabilised, the flow is lower, since the pressure gradient is lower too.

[Kristi]

Now that I'm up to 9, the subtle differences in taste would indicate that what you're saying is exactly right.
Thanks!
Kristi