The general rule for using a percolator coffee maker is adhering to a ratio of 2 teaspoons of coarsely ground coffee for every cup of water. Use less coffee for a weaker taste and more coffee for a bolder, more bitter flavor.
Percolator coffee makers work by boiling water in a reservoir, causing water vapor to condense and filter through the grounds. The ideal water temperature for a percolator system is between 195 and 200 degrees Fahrenheit. Percolators work best with low-acidity beans, because the process these machines use to brew coffee can cause over-extraction of the beans, resulting in a bitter taste if the beans are highly acidic.