Hi,

here is a short video of a pull with my beloved Brugnetti Aurora.
enjoy it:)

What a lovely machine!

Thanks for sharing!

Absolutely lovely, pull and machine both!
-Richard

Juanjo wrote:here is a short video of a pull with my beloved Brugnetti Aurora.

In the same spirit of the long-dormant Videos of espresso extractions thread, I hope you don't mind some play-by-play commentary. Bottom line: The extraction starts out uneven and gets progressively worse.

In the first frame below, note how the front section is dark with a stalled flow while the back flow is fully developed and its color is lighter. Most of the coffee is flowing from the back third of the puck. My guess is the distribution is more dense where the ground coffee naturally lands (?). Rotating the portafilter slowly as the grounds fall may help.



In the next frame, the back quadrant has blonded. The stream starts to pull to one side; this is a dead giveaway that the coffee is spent. IIRC, according to my chemist friend, it's caused by a change in the surface tension of the fluid as the constituent extracted solids decrease and the water content increases.



In the final frame below, the pour is hooking to the right and showing signs of "barber pole" striping. Channeling like this is obvious with a bottomless portafilter, but still visible with spouts. Generally the split flow will curve sharply inwards, or the color will blink back and forth between light/dark as the single pour from the bottom of the basket flits between the spouts.



My best guess is the grinder, but there's another possibility: Breaking the puck adhesion on the piston uptake. Most levers pull air through the puck on the upstroke. I don't know if the Aurora does, but if so, keeping the portafilter loosely engaged until just before the pressure is applied can help.

How did it taste?

hey Thanks..

Dan,
thanks a lot for the "critique".
I did notice that curve to the right.. but beside a visual effect didn't do much to the shot it-self.. it tested VERY good.. I put a tea spoon of brown sugar and pretty much I have to push it down..

I also noted the channeling.

Aside from Dan's recommendations about rotating the PF while grinding into the basket, I personally find that it helps to tamp less hard than you appeared to and to do so only once without twisting. A lighter tamp may require a slightly tighter grind of course.

Grinding fine and tamping lightly also seems to make things more immune to any of the "suction" on pulling up the lever that Dan mentions, though doing things gently and maybe locking the PF in on the upstroke will also help.

Once again: lovely machine!

But how did it taste? Remind me never to show Dan one of my pulls!

it tested VERY good.. I put a tea spoon of brown sugar and pretty much I have to push it down..

the prosecution rests.

jon

RegulatorJohnson wrote:the prosecution rests.

Ignorance is bliss.

If this site is to live up to its claim of being "your guide to exceptional espresso", we must be willing to call out errors in barista technique. If Juanjo enjoys a mélange of under and overextracted espresso with a dose of brown sugar, more power to him, but it's my bet that he'll enjoy properly extracted espresso even more.

dont sugar coat it, dan... tell us how you really feel.