Is there a term for when the tamper has moisture on it and it pulls up some coffee with it? It is very annoying when it happens. Usually my fault because I have a rubber tamping pad and I did several shots and some hot water dripped from the basket/bottom of the portafilter.
I would call it a "coffee tag" I guess. I find it ruins the puck.

Yes, NSEW means subtly rocking the tamper in those cardinal directions after the tamp. The goal is to seal the sides, prevent donuts, and generally promote a more even extraction. Nutating is an alternative. I did the former for several months and have switched to the latter to discern if there's a difference.

I had read Matt Perger's subscription, he do not encourage polishing the puck, but I like to polish it, it's beautiful

I haven't heard that, but I have heard that knocking the portafilter between the tamp and polish can cause channeling.

I think some like to do that (tamp, knock, polish) because it knocks the grounds off the sides, but the problem is that it could also cause fractures in an already tamped puck, so the best practice is not to tap or knock the portafilter after tamping. As for the polish, it probably doesn't help much, but shouldn't hurt as ling as it's done gently. I always do a little polish spin because it feels satisfying, and I like how nice and smooth it leaves the surface.

It's a bit different from polishing, but I like to spin my tamper before tamping. It seems to compress the grounds in a more uniform fashion, although I haven't done any comparisons to determine whether it helps with an even extraction or not

jeffreylam98 wrote:I had read Matt Perger's subscription, he do not encourage polishing the puck, but I like to polish it, it's beautiful

Matt who? He is entitled to an opinion like the rest of us.

wsfarrell wrote:Spinning a tamper without pressure is what people call "polishing," and has no effect on anything---it just seems like a fun thing to do. If you turn the tamper while applying pressure, that might have some unwanted effects.

+1 - I would struggle not to polish... it's addictive

wsfarrell wrote:Spinning a tamper without pressure is what people call "polishing," and has no effect on anything---it just seems like a fun thing to do. If you turn the tamper while applying pressure, that might have some unwanted effects.

Agreed. I do it on every shot.

jeffreylam98 wrote:I had read Matt Perger's subscription, he do not encourage polishing the puck, but I like to polish it, it's beautiful

Matt is without a doubt a professional with lot of experience, however it seems like his claim is supposed to be supported with one picture of someone getting it wrong lol https://baristahustle.com/blogs/barista ... n-you-tamp
Also: "If you're still applying any force OR lift and drop the tamper on the grinds while spinning (a very common occurrence) you'll change the distribution of grinds and make the extraction less even." I do polish but I don't apply any force nor lift and drop the tamper, so should be allright