I've been making decent espresso shot for a while however lately it gets kind of messy.
During the initial extraction all is well but about 5 seconds in it gets really messy and coffee spats everywhere.
No indication of channeling !!
Level tamping with WDT.
Vibiemme domobar (9bar)
VST 18gr (18gram dosed)
58,5mm motta tamper
Mazzer sj (doserless mod) with 25kg old burrs.
The beans have been frozen 5 days after roasting and been defrosted (for about 7 to 9 days and kept in an airsealed container)
It really grinds my gears, I've been doing nice shots for a while and this is the first time it happens without changing anything.