Certainly sounds like it. If in doubt you can also get into the habit of checking the surface of the puck afterwards to see if there are visible craters/holes/cracks, including around the outside edge. Consistent puck preparation, including even tamping, is as you recognise, key. I am a dosing cup fan, others swear by a variety of distribution tools to achieve an even density of grounds in the basket. I know my tamping can sometimes be a bit iffy so before I tamp I use an inexpensive Motta levelling tool to give me an absolutely flat surface onto which to place my tamper.

 

I'm using - OCD? Tool to even the surface, before that a toothpick and between that I hit porta with palm horizontally and vertically, 99% sure my channeling occurs from uneven tamping. It's the way I hold it for some reason, after tamping it's always leaning unevenly, sounds like something easy to correct yet I keep repeating the same....

 

Well apologies for the pseudo psychological self help mantra, but self awareness in this instance sounds like 99% of the solution... The other 1% is practice, practice, practice... Try holding the tamper in an unconventional, even uncomfortable way? I was once told (by a barista trainer) to tamp using the tips of thumb and three fingers evenly spaced around the top of the tamper base. I think that made me more aware of the attitude of the tamper. But whatever approach you take, it still sounds like practice.

 

This is exactly what I do ^^ I start thinking that I put too much pressure with either my thumb or fingers as I tamp but yeah finding a different way that I hold the tamper so it works for me might be best solution. Thank you.

 

Make sure the holes in your portafilter are not clogged, that was an issue for me when I got my bottomless portafilter.

 

It happened first time I used it and so it came with new basket. Regardless I have still checked if they are not clogged