ETisME wrote:I love how you present your process and findings! the Moonraker looking really sweet in the photo

Just wondering if by chance you can do one without any WDT all together? (just tamp). one thing I still don't understand is: clumps are produced by grinders, which shouldn't be as dense as those produced by the tamper.

Why WDT matters if a calibrated tamper make densed peck through equal pressure? shouldn't any clumps produced by grinder should become similarly dense?

I can't speak for John, but there is plenty of research data (including some excellent work in Australia by Socratic) showing that clumpy areas of the puck once tamped, produce non-uniform density within the puck. Water travels the path of least resistance causing some of the puck to be under extracted, while other parts are over extracted. WDT, if done correctly, evens all this out.

As Bob suggests, I'm not going down that rabbit hole again. And I've never claimed that you need to stir grinds for a good extraction. Let me quote from my original WDT article:

Grind, dose and distribution are critical to fine espresso. But unfortunately for home baristas, most high-end espresso grinders are designed for the fast-paced production of a commercial environment. Smaller capacity grinders found in even the best equipped home espresso environment may suffer from clumping, static, and uneven distribution... We can hope that these design flaws will eventually be addressed in home grinders. But until then, there is a simple, inexpensive solution to grinder problems: the Weiss Distribution Technique, or WDT.

That was written in 2006 (italics added). Several grinder flaws have been addressed since then, and nowadays there are many good choices in single dosing grinders for the home barista. I can easily get a good extraction with a large conical grinder, classic espresso blend, and minimal puck prep. But when I stagger into the kitchen for my first cup of coffee in the morning, I'm not at my best. So I continue to weigh my dose and practice careful puck prep (WDT) because these steps take relatively little effort, increase extraction consistency, and safeguard against the occasional uneven grind distribution.

Got the DHL notice for mine. Coming this Monday. At which time all my problems will have been solved

You lucky dog!!! Ultra or Standard model?

Thank you for the test, RapidCoffee!

DHL just delivered mine. Very well made and heavy. The pre installed needles are of different lengths, and interestingly the short needles magneto holders cannot accept long needles due to different needle diameters. WDT can be done with one hand due to the friction of the rubberized bottom. It did a good job of WDT and leveling on the first try. No channeling observed.

Standard.

Just pulled my first two double shots using it. I have to say, it seems way better at WDT than anything I tried previously.

I had a Normcore spinner WDT that left visible striations because the needles just moved in a circle - the exact problem the Moonraker is meant to address. I'd tap the PF after using it to try to settle and 'fill' the channels. But the results were inconsistent. Comparing the output to that from the Moonraker, it was no contest. Both shots pulled evenly, no channeling observed, exact same time to get the exact same ratio in/out. And perhaps therein lies the greatest benefit: consistency.

And I concur with @acg - very well made, heavy, a sense of quality in the hand. Worth the price? Eh. Life is too short to dabble in such questions. I already paid four figure for my machine, and my grinder. What's a few hundred more?

For those enterprising folks (with access to a 3d printer) who want a very similar device, check out this

https://www.printables.com/model/481587 ... o-wdt-tool

Otherwise, this looks like a pretty cool toy.

acg wrote:DHL just delivered mine. Very well made and heavy. The pre installed needles are of different lengths, and interestingly the short needles magneto holders cannot accept long needles due to different needle diameters. WDT can be done with one hand due to the friction of the rubberized bottom. It did a good job of WDT and leveling on the first try. No channeling observed.

Interesting that the needles in the device are of different lengths. I've heard this from more than one source. The different needle diameters is something new! Haven't heard of this on any WDT rotating tool to date.

For you and NewCoffeeGuy1, how many rotations are necessary to achieve a uniform bed?

Each turn is only a half circle, and 8-10 turns are about enough for me.