Good coffee beans alone will not guarantee a tasty cup, according to Food & Wine. How finely or coarsely the beans are ground also matters, since grind size affects how well coffee brews and how it ultimately tastes.
Michael Phillips, global director of coffee culture and hospitality at Blue Bottle Coffee, said several factors influence which grind works best, including the brewing method, technique, the coffee itself, its roast level and the age of the beans. He said finding the right setting for each coffee is a mix of art and science.
How Blue Bottle tests its grind
Phillips said that every morning in Blue Bottle's cafes, staff brew several cups while keeping all other conditions the same and only adjusting the grind slightly coarser or finer to find the best setting for that day. He said the difference may not even be visible to the eye, but a wrong grind size can make coffee too bitter from over-extraction or too sour from under-extraction.
Matching grind to brewing method
Phillips recommends a coarser grind for French press and a finer grind for filter brewing methods. He said espresso machines generally need a specialized grinder capable of producing a very fine, precisely adjustable grind.
He added that water quantity should be decided first based on how much coffee is wanted, followed by the amount of coffee needed for the desired strength.
