Success.
Two days on the trot with no gushing or spurting and a perfectly clean and neat cone of espresso from the bottom of the pf in a 25sec extraction.
What changed?
The Ceado E5P is not a low retention grinder and in spite of hoovering it out after every grind I found a good 5mm of compounded grinds adhering to the outer circumference of the lower burr. Disassembly, thorough clean and instant transformation. The burr surfaces were already clean.
I use bellows because of this issue and I guess they were blowing some of the older grinds into the puck at the end of the grind.
I discovered the retention issue when I first bought the grinder - 25g of beans in … 18g out… hence the bellows and the hoover.
My next grinder will be low retention…