We favor the use of the "doser," built into the grinder, as a "dispenser" instead.  We train to "grind on demand" and sweep the freshly ground coffee rapidly into the porta filter till the basket is filled to the rim, shaving off the

Fill to Rim and Shave Off Excess

excess with a wooden or plastic spatula.  (We do not like the use of fingers to do this).  Since this is technically "volumetric dosing," it is very important that the density distribution within the basket be uniform, for shot consistency.

 

To accomplish this, we require that the doser handle be pulled at a steady, but rapid rate to prevent accumulation of ground coffee inside the doser chamber.  Otherwise, the very next sweep will cause a large clump to drop into the basket which will compress the ground coffee underneath, thereby creating a region of high density inside the basket.  This will affect the total dose as well as the distribution of coffee within the basket, both affecting shot consistency.  After some practice, most baristi are able to dose to within 1% by weight.

 

In the beginning, most people tend to tamp at an angle. We have devised several tools, with the help of John Blackwell at La Marzocco, USA to help trainees learn to tamp "straight."

Tamping Block

First of these is a support bracket to hold the porta filter level even when it has only a single spout. The same bracket can be used with two spouts and with no spout, although in those two cases that bracket may not be necessary at all to keep the porta filter level for tamping.

 

 

The second tool is actually a modified tamper into which a calibrated step is built in.  By tamping till the step on the tamper sits flat on the shoulder of the basket, we accomplish two important goals: (1) tamping level; and, (2) tamping to exactly the same pressure 

regardless of how hard one presses down.  

 

In a production set up, if more than one barista is working, it is very important that all baristi tamp to exactly the same pressure.  It is just not practical to re-adjust grind between shots if each of the baristi working the same shift is tamping at a different pressure.  Hence it is common practice for a shop to standardize on a tamp pressure at least within each shift, if not across all shifts.

 

Most baristi are trained to tamp to a defined pressure by the use of a bathroom scale.  With the stepped tamper, a 5' 1" tall female barista weighing 90 lbs and a 6' 3" tall male barista weighing 300 lbs are both compelled to tamp to exactly the same pressure, provided the dosing is done precisely.

 

This protocol puts extra demand on uniform dosing density.  But that is always necessary for shot consistency.  This technique makes it the only variable that is important to be controlled.