Posted Sat Feb 18, 2006, 9:34am Subject: "Settling" the Grounds...
Since I cut a hole in my portafilter, it's become obvious that I wasn't doing a great job with distribution and tamping. I've tried different ways of dosing, leveling, and yet I was still getting little sprites during extraction.
I tried something new this morning that seemed to make a difference. I had an old electric scribing pen in the workshop (used for scribing on metal tools for identification). After dosing, while I still had a "mountain" of coffee, I simply turned on the scribing pen and held it against the bottom of the filter for about 5 seconds. The "mountain" just kinda melted down, almost to the level I'd expect after tamping. I also noticed cracks filling in with coffee falling from higher up. And I did NOT get any sprites this time. I'm gonna experiment some more with this!
I realize, for the pros out there, this will be completely useless in a high-volume environment, but if this proves effective, it wouldn't be too hard to make a device suitable for shop use on which you could set your PF on for about 5 seconds before tamping.
Everman Senior Member Joined: 25 Nov 2004 Posts: 1,040 Location: Coffee Land Expertise: I love coffee
Espresso: Valentina Levetta, Elektra... Grinder: Mazzer Mini Roaster: Hottop
Posted Sat Feb 18, 2006, 10:27pm Subject: Re: "Settling" the Grounds...
After I dose and evenly distribute the grounds a bit I'll tap the Pf on the counter, then finish distributing the grounds and then tamp. Adding that tap to settle the grounds down seems to have really helped a lot towards great consistency.
Posted Sun Feb 19, 2006, 1:42pm Subject: Re: "Settling" the Grounds...
Others have reported that tapping it will cause cracks, and cause it to pull away from the sides. My experience confirms this.
I repeated the experiment last night with the scriber. Same results--the grounds appeared to shrink in volume by about 30-50% before tamping. No channeling.
Jasonian Senior Member Joined: 8 Aug 2005 Posts: 3,856 Location: Lubbock, TX Expertise: Professional
Posted Sun Feb 19, 2006, 7:44pm Subject: Re: "Settling" the Grounds...
JR Said:
Others have reported that tapping it will cause cracks, and cause it to pull away from the sides. My experience confirms this.
I repeated the experiment last night with the scriber. Same results--the grounds appeared to shrink in volume by about 30-50% before tamping. No channeling.
If the PF is forcefully knocked against the counter, this will happen. If the PF is knocked on the sides with a tamper AFTER the puck has sem-formed, this will happen about 50-60% of the time. If the PF is allowed to fall in a controlled manner from a short distance onto the top of the counter, the force of multiple G's tends to press the grounds together, while still allowing freedom of lateral movement since there is a lack of overhead pressure.
I've found that this NEVER cracks the puck. I do, however, think that simple vibration allows the grounds to separate quite easily as it sort of gives friction a slip and allows the grounds to fall almost exactly where they would in a perfect situation.. that is, friction not affecting the settling of the grounds (obviously impossible, but ideal).
I do think that a controlled drop following your vibration technique would add farther benefit by gravity (and not friction or manual (possibly uneven.. even if slightly) force) compacting the grounds into the near-ideal shape of the puck, which would compact them enough that the position would not be easily jarred during tamping.
Hmm.. what do I have that will have this vibrating effect.. (I wonder if a soft-fibrating tamping pad.. with a switch, of course, would be beneficial).
Posted Sun Feb 19, 2006, 9:06pm Subject: Re: "Settling" the Grounds...
Jasonian Said:
...Hmm.. what do I have that will have this vibrating effect.. (I wonder if a soft-fibrating tamping pad.. with a switch, of course, would be beneficial)...
And you see where I'm going with this. If you could rig your grinder base with such a pad (with a pressure-sensitive switch, of course) this would take only a few seconds--no longer than the routine "leveling" that we normally do.
I repeated this again tonight. This time, I tried different adjustments. The scriber has a small adjustment knob that alters the amplitude, but not the frequency. I found that there is a small range that is good. Too little vibe, no effect. Too much, and it just scatters grounds.
I also held the scriber in place longer, to see what would eventually happen. Two sides rose up and the puck kinda folded up in the middle. It also started forming clumps. So, after about 5 seconds, it was no longer beneficial. Even after all this, I tamped it, and had no evidence of channeling.
Jasonian Senior Member Joined: 8 Aug 2005 Posts: 3,856 Location: Lubbock, TX Expertise: Professional
Posted Sun Feb 19, 2006, 9:57pm Subject: Re: "Settling" the Grounds...
JR Said:
And you see where I'm going with this. If you could rig your grinder base with such a pad (with a pressure-sensitive switch, of course) this would take only a few seconds--no longer than the routine "leveling" that we normally do.
I repeated this again tonight. This time, I tried different adjustments. The scriber has a small adjustment knob that alters the amplitude, but not the frequency. I found that there is a small range that is good. Too little vibe, no effect. Too much, and it just scatters grounds.
I also held the scriber in place longer, to see what would eventually happen. Two sides rose up and the puck kinda folded up in the middle. It also started forming clumps. So, after about 5 seconds, it was no longer beneficial. Even after all this, I tamped it, and had no evidence of channeling.
That makes sense. I'm inclined to think that lower frequency vibrations would be best.. but not too low, obviously.
I saw where you were going with it. ;o) It's a great idea. I was just thinking about the EspressoCraft tamper/puck set.. and wondering how simple it would be to make that a vibrating puck instead of a solid puck.. just hit the switch, and it turns from tamp-pad into automatic distributor, and then back again.
silver2k Senior Member Joined: 31 Dec 2005 Posts: 74 Location: PA Expertise: I like coffee
Espresso: Quickmill Vetrano Grinder: Mazzer Super Jolly Roaster: Behmor
Posted Sun Feb 19, 2006, 11:01pm Subject: Re: "Settling" the Grounds...
I do this already to some degree. I hold the portafilter against my Super Jolly while it runs. I can see the clumps break up and the grounds settle - it works great, you just have to be careful of overdosing, I had to grind a little coarser after doing this.
Posted Sun Feb 19, 2006, 11:05pm Subject: Re: "Settling" the Grounds...
silver2k Said:
I do this already to some degree. I hold the portafilter against my Super Jolly while it runs. I can see the clumps break up and the grounds settle - it works great, you just have to be careful of overdosing, I had to grind a little coarser after doing this.
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