It is often said that your grinder is the most important piece of equipment that effects how Epic your coffee is. Well, it’s true. Even coffee that was ground just seconds before brewing will produce a lousy cup if it was ground with a hammer. It is important that all of the grounds in your brew are the same size.
If some grinds are too large for your brew method, then they will be under-extracted, meaning that much of the flavor and wonderfulness is left behind. It will introduce sourness to your cup, and your coffee will lack its characteristic sweetness and body.
If some grinds are too small for your brew method, then they will be over-extracted, meaning that more flavor was taken than the coffee had to give. This results in coffee that is bitter and causes a bit of a dry mouth.
With an uneven grind, you get all of these unpleasant qualities in your coffee. This is why blade grinders are a poor choice. A solid conical burr grinder provides a nice even grind, and a great cup of coffee.