Go to the Article: Extraction Matters
The English accent definitely pairs well with a cup of coffee...
No where does this tell one HOW to get the perfect extraction...it just tells me it exists
check out James Hoffman's youtube channel. He'll tell you more than you EVER NEEDED to know about coffee extraction and how to get that right
The coffee class goes into Extraction here: https://www.chefsteps.com/activities/getting-the-good-stuff?context=coffee