Took me 3 months to figure out my espresso was channeling

I kept getting sour shots from my Gaggia Classic, thought it was the beans or grind size. Finally looked at my puck prep under a magnifying glass and saw tiny cracks forming after tamping. Anybody else spend way too long diagnosing a simple tamping issue?

2 comments

2 Comments

skyler_fox721mo ago

Did you check if your tamper actually fits your basket right? I spent two months chasing channeling issues just to find out my 58mm tamper was actually 57.5mm and leaving a tiny gap around the edges. It was barely noticeable but it was enough to make the water find the path of least resistance around the sides instead of pushing through evenly. Got a precision tamper that actually matches the basket walls and the difference was night and day. Might be worth measuring yours with a caliper if you haven't already.

olivia_wilson1mo ago

Hang on @skyler_fox72, I gotta push back a little on the tamper size thing. Most 58mm baskets are actually a hair bigger than 58mm, so a 57.5mm tamper isn't necessarily the enemy if it sits centered. The real issue with channeling for me was that I was over-tamping and cracking the puck surface, not the edge gap. Also, those cheap plastic distribution tools are way more likely to cause weird density pockets than a slightly undersized tamper, in my experience.