A paper on Espresso Extraction - Page 3

[Martin]

(holding off on WDT for now). My main challenge
now is that sometimes the coffee is way below the portafilter rim, making distribution a bit
of a challenge

I use the WDT. Next, I perform a couple of north-south shakes; then some east-west shakes wrist rigid and elbow stable at hip. This can do a nice preliminary job of leveling and closing the gap left by removing the yogurt cylinder (demonstrating as I type). I follow by simply resting my heavy tamper on the loose grounds to prepare for a NSEW tamp. Lastly, a very light pressure tamp (guessing 5lbs).
Martin

[AndyS]

This sounds relevant to arguments for or against pre-infusion. But how? Seems likely that the smaller diameter basket and relatively greater headroom on the La Spaz (at my current 15g) would factor into the machine not pre-infusing; or possibly its a reason for a machine like the Tea going with pre-infusion.

Hi Martin:

In my view, there are many different methods of "preinfusion." The E61 spring-loaded chamber is one style. A slow initial buildup to pressure (via gicleur, pump hesitation, or big headspace) is another. Whatever name you give, the result is pretty much the same.

[another_jim]

This sounds relevant to arguments for or against pre-infusion. But how? Seems likely that the smaller diameter basket and relatively greater headroom on the La Spaz (at my current 15g) would factor into the machine not pre-infusing; or possibly its a reason for a machine like the Tea going with pre-infusion.
Martin

I agree with Andy, a well pulled shot with no preinfusion will taste just as good as one with. However, shot to shot pulling consistency seems much improved by longer dwell times (however this is arranged).

Luca has been telling me about Paul Bassett's technique. Two of the notable things is that he varies dose from extreme over dosing to extreme underdosing, the other is that he bangs the bejeesus out of his PF before he levels and tamps. It occurred to me that one way of getting consistency with the wide variation in dwell times such dosing changes create is to make sure the fines are at the bottom of the basket before one starts. Short of doing a full WDT, a lot of banging may be the best way to do this.