Looks like Barry is trying to mind meld with that portafilter, or heat it with his barista thermal vision.

But back to the topic at hand. Personal habits aside (come on guys, that is going a little over the top ), when you down dose a basket you have more headroom (space between the puck and shower screen). When you pull the shot the coffee cake swells but in a down dosed basket, or a properly dosed basket depending on who you ask, the puck does not contact the shower screen. When you stop your shot, the three-way valve or solenoid opens evacuating the pressure in the portafilter. Because the puck has not swollen and compressed against the shower screen, the top of the puck is left sludgy and loose from the rapid depressurization. I also notice that my shower screen gets dirtier from more grounds being sucked up against the screen.

On an overdosed basket, the coffee cake swells during the shot and the surface compresses against the shower screen. That pressure holds the puck in place and together when the three-way opens leaving you with a nice little round brownie puck.

My Isomac produces a firm puck, the Vibiemme Domobar Super produce one that looks like wet sand on top and my Elektra A3 is somewhere in between. I bet if you weigh your baskets you are getting around 15 grams in the dose, if you go back to the mid tamp, dose more and finish tamp you are probably getting 18-19 grams in the same basket.

cannonfodder wrote:I bet if you weigh your baskets you are getting around 15 grams in the dose, if you go back to the mid tamp, dose more and finish tamp you are probably getting 18-19 grams in the same basket.

How would you avoid clumping in the second half of the dose if one normally uses the WDT(stir grounds with yogurt container on top)? Thanks for the useful input.

Owen

Ken Fox wrote:As a sometimes world traveler who spends about 2 months a year in France, from where I type this, I can tell you for sure that there are places I have not gone back to based upon my bowel movements afterwards.

I bet they served great coffee, though.

cannonfodder wrote:Looks like Barry is trying to mind meld with that portafilter, or heat it with his barista thermal vision.

I had to look at the picture again and noticed that someone had stuck a pencil up the barista's nose. Now that's what I call mind melding.

owlbass wrote:How would you avoid clumping in the second half of the dose if one normally uses the WDT(stir grounds with yogurt container on top)? Thanks for the useful input.

Owen

My Aerolatte (Nemox/Lux) has a problem of severe clumping and I also mid-tamp, to reduce channeling and early blonding. The problem is, the extra time spent with the mid tamp and distribution, also leads to heat loss from the group. To speed things up, I copied dsc's weapon of mass distribution, using a wine cork and about 20 needles.

You could use the WMD, in conjunction with the WDT method, a quick jab in the clumps, followed by a raking stir of the grounds' surface, may do the trick. However, if you're getting equally good pours, without the mid-tamp, I would live with the soggy pucks.

Bertie

I am achieving superb, world class, puck firmness. My espresso is horrible though.

owlbass wrote:How would you avoid clumping in the second half of the dose if one normally uses the WDT(stir grounds with yogurt container on top)? Thanks for the useful input.

Owen

Sorry about the slow response, I have been in Vegas for a week for the Citrix I-forum conference. My recommendation, go ahead and dose the entire amount into the basket, do the WDT and then before you remove the cup, give the portafilter three or four downward thumps onto the table or tamping stand. Not too hard, just hold the portafilter two or three inches above the table/tamping stand and let it fall down while holding it level. The thump, thump will settle the grounds into the basket and you should be able to remove the containment cup and then tamp, or get a triple basket which is about what you dosing from the sounds of things.

cannonfodder wrote:Sorry about the slow response, I have been in Vegas for a week for the Citrix I-forum conference. My recommendation, go ahead and dose the entire amount into the basket, do the WDT and then before you remove the cup, give the portafilter three or four downward thumps onto the table or tamping stand. Not too hard, just hold the portafilter two or three inches above the table/tamping stand and let it fall down while holding it level. The thump, thump will settle the grounds into the basket and you should be able to remove the containment cup and then tamp, or get a triple basket which is about what you dosing from the sounds of things.

Firm puck, tasty shot, all on second try. Thanks for you help.
Owen