I have a three-edged ‘Levelling’ tool that looks very similar to the one @DavecUK has.
I did manage to read Dave’s review before he pulled it, and, once I got over the shock of him having splashed out £3.85, or whatever it was, on a coffee gadget, I too was surprised to read that he was rotating it, only, clockwise.
The only basis for that surprise was me comparing it to the way I used to use mine. I say used to use it, as it has been confined to a cupboard since I acquired, initially, a LevTamp and then, subsequently, a PUQpress.
Truth is, I don’t think I ever gave the process a great deal of thought. Rather, from the get-go, it seemed intuitive to rotate the leveller anti-clockwise for a few turns…..thinking that the sharper edges would more readily collect, push, level and, evenly distribute grinds. Then rotate a few clockwise turns….. to finesse the puck surface prior to conventional tamping.
However, as Dave has pointed out, there is an almost inevitable issue with anticlockwise turning. Dependant upon coffee / grind and, probably, atmospheric conditions, a small amount of coffee can collect behind the three steep edges. This either remains as a small, loose, deposit on the otherwise flat puck or, it sticks to the tool itself.
Anyway, this thread prompted me to get the tool out of the cupboard and take a look at what it actually achieves.
The idea was to try and observe the mechanics of the process and so did not involve using the resultant pucks to make espresso. There is no way that my methods can claim to be scientific but I did try to make them semi-sensible and, for what they are worth, my observations objective.
The tool is intended to be rotated with it’s shoulder running on the basket rim and so, needs to be set to a suitable depth.
The centre of the base and the three radials are nominally flat and equate to about 50% surface area.
The other 50% is made up of the three sections which cut back 3mm and slow taper to nothing.
Immediately you drop the tool down onto the coffee bed, 50% of the puck is ’tamped’ nominally flat, to the fixed depth.
If you rotate anti-clockwise, a small amount of grinds gets swept by the sharp shoulder. This either ends up left on top of the puck or stuck to the tool. It rarely if ever becomes integral with the puck. The amount of coffee wasted if it sticks to the tool is insignificant. The amount of coffee that may be loosely deposited on the otherwise flat puck is insignificant if later tamped.
If you rotate clockwise, the coffee that, initially, takes up the space of the slow tapers, gets compressed and flattened. IMO it does NOT get moved or distributed around the puck. The puck surface will be flat and smooth. It’s a great basis to aid getting a level, subsequent, manual tamp.
There are three sections to this tool. By the time it has been rotated little more than 120º, a third of a turn, it has done as much work as it is going to do!
Unless set too deeply, the compaction density of the puck will be limited by the shoulder setting.
Any significant unevenness in the initial bed of grounds will be reflected by uneven density of areas within the puck.
In summary, it provides a quick way to level the surface of a puck. I don’t believe it significantly improves the distribution of the coffee grounds. The consistency of density throughout the resultant puck is a factor of preparation, such as stirring and or shaking down, done prior to its use.
I’m not suggesting that it’s an espresso prep killer but, is it particularly beneficial over a fixed depth tamper?
There are similar tools, such as the OCD, which has four somewhat deeper segments, that may do a far better job than I believe mine does.