Some percolators are for use on top of the stove whilst others
are electrically heated. The percolator coffee brewing method
involves cold water being poured into the percolator and ground
coffee being placed in a metal basket. When the water boils it
is forced upwards through a central tube over the ground coffee,
filters through the basket and then drops to the bottom of the
pot. The grind recommended for a percolator is usually medium.