I love it when friends and customers share how they are upgrading their espresso extraction technique... and the gains they're seeing!
David recently let me know that he'd started to redistribute the grounds in his portafilter prior to extraction using a humble toothpick and had experienced significant improvement in the evenness of his extractions. Take a look at his YouTube channel where you can see an extraction from four years ago (the "donut extraction" is pictured above)...
David's old espresso extraction technique
... and one from four days ago...
David's current espresso extraction technique
He tells me that his espresso has never tasted better and that the crema is incredible.
Redistribution refers to moving the ground coffee around with some sort of implement... I use a mini whisk, some people use specific puck rakes, anything will do... prior to tamping the puck. This process causes the coffee puck to be homogeneous in consistency and that means that the pressurised water from the group head finds it difficult to preferentially track through lower resistance pathways (channeling)... all of which leads to more even extraction across the entire puck and optimised extraction of all of that coffee goodness! Without redistribution one is prone to donut extractions where there is lower resistance around the circumference of the portafilter and the espresso initially extracts in a ring near the edge of the basket. This is a telltale sign that extraction isn't as good as it could be!
Dave, as a side note, I quite liked the new age music accompanying the video from four years ago... I was a little sad not to hear something similar on the 2025 version!
Enjoy!