Grind size is usually the first variable adjusted during dial-in. Finer grinds tend to slow flow and increase extraction; coarser grinds do the opposite.
The particle size of ground coffee, typically adjusted finer or coarser to control flow and extraction.
Updated February 18, 2026
Grind size is usually the first variable adjusted during dial-in. Finer grinds tend to slow flow and increase extraction; coarser grinds do the opposite.