Percolator - How a Percolator Works
The percolators use a pump system that brings hot water through the a tube and disperses it over the coffee grinds on the top basket. The pump tube is a long tube that sits vertically in the middle of the percolator and supports the basket. The basket of the percolator has an opening where the pump stem is inserted. There are tiny holes in the basket that are large enough to allow the water to pass through, but not the coffee grounds. (paper coffee filters are not used).
Before placing the basket, the desired quantity of water is poured into the water chamber of the pot. It is important that the water level be below the bottom of the coffee chamber.
After the percolator starts to work, the temperature rises until the water in the bottom chamber boils. When the water boils the air bubbles flow upward and through the bottom opening of the tube. The tube forces water up toward the basket, where it is dispersed over the coffee grounds. This water then seeps through the coffee grounds and leaves the coffee chamber through the bottom, dropping back into the lower half of the pot. The rest of the water at the bottom is meanwhile also forced up the tube, causing this whole cycle to repeat continually.
As the brew continually seeps through the grounds, the overall temperature of the liquid approaches boiling point, at which stage the "perking" action (the characteristic spurting sound the pot makes) stops, and the coffee is ready for drinking.
Brewed coffee left on high heat for too long will acquire a bitter taste.
The Washer
There is a washer mechanism located on the bottom of the pump tube. The washer must always move freely. If the washer gets clogged with coffee grounds or has a build up of mineral deposits the unit will not be able to percolate the coffee properly. The coffee grounds can be removed from the washer with a wooden toothpick or by running under water. For cleaning instructions please see the instructional brochure or Click Here for general cleaning information.
The Pump Tube
The pump tube must be properly seated in the percolator or the unit will not work properly. If it is damaged or not positioned correctly, this will make it impossible to pump water. Always make sure that the tube is seated vertically so that it is in the center of the heating unit and that it is not bent/damaged in any way
Diagram
This is an example of how the percolators work
