another_jim wrote:Um, the nutate part distributes and grooms the edge.

Agreed, I still believe that this occurs not because one compresses or "seals" the edge (this is akin the the old belief that chefs had that searing meat "sealed in the juices" which is also a misconception but which also does not invalidate the technique) per se, but because it is a systematic structured way of progressively redistributing and compressing the puck which results in a nice symmetrical puck shape with an even coffee distribution.

another_jim wrote:Take basket/PF directly from the grinder, grounds untouched,
-- then nutate,
-- then press lightly,
-- then make the shot.
If you do any other sort of distribution, it's a complete waste of time.

I don't think we're necessarily in disagreement. But the converse of your last statement is equally correct: if you do any other sort of grinds distribution, then the nutating portion of the tamp is a waste of time.

Has anyone noted the similarity between the nutating tamp and Stockfleths maneuver? Both use a circular motion to push grinds towards the center of the basket. I view these as distribution-enhancing techniques, to be applied before the actual tamp compresses the grinds in a straight downwards direction.

The nutating tamp certainly has the advantage of simplicity.

another_jim wrote:grooms the edge.

More arcana I don't understand

If we look back at our stacked spheres, which coffee clearly is not, the largest gaps are at the boundary layer, in this case the basket. Regardless of how small the particles are, the edge will always have the most free space.

another_jim wrote:If you do any other sort of distribution, it's a complete waste of time.

Didn't we already cover this in How important is tamping?

Now and then you come across a machine that will favor a little voodoo action, but most of the time it is not needed. You can simply try it out; if it makes a difference, use it. If it does not, then don't.

Regardless, it is just fun to say nutating.

FYI, that was a very old video. I gave up the portafilter tap about two years ago.

I confess an interest in all distribution rituals if they seem to have a positive effect on the cup. My goal is to try all forms of distribution to figure out which one makes the best cup and then after that figure out which one I can do the quickest without dropping the quality of the cup at all. If a ritual takes 30 seconds instead of 3 seconds, but produces better espresso I'll jump on board. If the process is voodoo, but it produces better espresso feel free to crown me the king of voodoo. I always want to know why things work, but more important to me is the simple question "does it work?"

another_jim wrote:Um, the nutate part distributes and grooms the edge.

Take basket/PF directly from the grinder, grounds untouched,
-- then nutate,
-- then press lightly,
-- then make the shot.
If you do any other sort of distribution, it's a complete waste of time.

Nutating is something I haven't played with much yet, but I plan to try. Jim, is it safe to assume that you get as even a distribution as possible as you dose or are you saying even that sort of distribution is a waste of time?

Also while I'm asking dumb nutating questions, as you nutate it is indeed like a coin spinning, not a rotation where the exact same point on the tamper contacts the coffee at all times (the former would be easier to do well, the latter would create a slightly different distribution).

The entire rim of the tamper presses down close to the entire rim of the basket, one point at a time, just like a wobbling coin. Look at my diagram or the film.

The nutating motion is a way of distributing and leveling, not of tamping down. If you distribute in some other way, you can either stop doing that and try nutating, or just skip the whole thing. I do it because it's fast and easy, and works well enough on my kit.

Ask Ian exactly what it does, I hereby appoint him the grand revolutionary explanator.

That's the only way to get the nutating to tamp to work in my opinion.

You're basically doing two things: nutating to distribute and level, then tamping to settle the basket. You just happen to be using the tamper to do both. It's a two birds with one stone approach. If you apply any tamping pressure while nutating, you are in my experience much more likely to get channeling.

Cheers

Mike

RapidCoffee wrote:Has anyone noted the similarity between the nutating tamp and Stockfleths maneuver? Both use a circular motion to push grinds towards the center of the basket.

It could be that I've always got it wrong, but for me the Stockfleths doesn't simply sweep into the centre, but also up against the circumference of the basket - it does both.

I think that's why the nutating tamp works better with an American C tamper for example, which adds a bit of the latter.

Cheers

Mike

Hi guys,

I have to say this, I wanted to post in this thread a few days ago and say that I'm surprised people actually think that nutating helps, but...

...it seems to work wonders on my Elektra :O even if I redistribute the coffee to create an even bed before tamping it's still worse than when not distributing and doing the nutating motion. With a heap in the middle, the nutating motion seems to help to secure the egdes and even when I get a donut extraction it doesn't go down the drain. It sort of heals itself and flow properly after a few seconds. Without nutating I can get even beading (with redistribution), but the shots go sideways mid-extraction for some reason and are worse than heap+nutating.

Regards,
dsc.

another_jim wrote:Um, if you say so.

But in actual mathematics, precession is 2D physics, the simple rotation of the axes of an elliptical orbit; while nutation is 3D analytical geometry, the motion of a tilted annulus touching a plane at one point and having its axis describe a circle parallel to that plane. This motion will inscribe a circle on said plane whose radius is the cosine of the tilt angle times the radius of the annulus.

I picked the word nutation, since that is the word for the motion I was describing. I never realized that it would give people trouble. If I had, I'd have called it the "coin flip tamp."

I'm excited that I almost understand this. "Nutation" made perfect sense to me first time I heard it. I'm not sure about "precession" as it's been too many years since I've navigated by the stars. Gonna have to dig out my old manuals. I remember precession as a source of error for inertial (gyro based) nav systems. As you travel over the earth, the gyro stays "level" to the point you left, except the earth is round... getting OT, here.

Anyway, I tried nutating my tamp this morning, having not read any of this thread, and got decent shots. Could be coincidence. Came here to see if I was doing it right, and I was pretty much spot on. I guess "nutation" is a perfect word choice.

I'd also suggest that rotation at the same time as nutation would not be necessary, but in case I'm rehashing, I'd better go read the rest of the thread.