Coffee percolators brew coffee by boiling water up through a basket containing coffee grounds. Because of its longer brewing process in comparison to drip or espresso machines, percolators require a coarser ground coffee to prevent it from tasting bitter. Use a burr grinder as opposed to a blade grinder for a more consistent grind when grinding coffee for a percolator. Blade grinders, usually the cheapest option, require you to grind the coffee beans until you think it is fine enough, while burr grinders grind the beans to your specified coarseness. Granules are also typically inconsistently sized when a blade grinder is used.
Remove the coffee bean hopper's lid.
Fill the hopper with the chosen amount of coffee beans, but do not fill past the hopper's maximum level. Replace the hopper's lid.
Turn the quantity selector on the outside of the coffee mill to select the amount of coffee to grind.
Turn the fineness selector on the outside of the coffee mill to "Medium/Coarse."
Plug the coffee mill into an outlet and press the "On/Off" switch to start grinding. The coffee mill will stop when the coffee is ground to the specified fineness.