Coffee percolators

Some people make their coffee in a pot that bubbles away on the hob. That pot may be a percolator or a moka pot. The two look alike, and they brew coffee in different ways.

How a percolator works

A percolator is a pot with a chamber at the bottom, a tube up the middle and a metal basket near the top. The water goes in the pot, below the level of the basket. The coffee goes in the basket, usually ground fairly coarse.

As the water at the bottom starts to boil, bubbles of steam push hot water up the tube. It hits the underside of the lid, spreads over the grounds and drips back down into the pot. This happens again and again, and it makes the "perking" sound people know.

Close to the boil, the perking turns into a steady gurgle, and the coffee is ready. Coffee left perking at the boil goes on brewing, and it turns harsh and bitter.

Stovetop and electric percolators

A stovetop percolator sits on the hob. The cook stops it by taking it off the heat or turning the heat down.

An electric percolator has its own heating element. Most electric ones turn the heat down by themselves at the end, and keep the coffee hot without boiling it.

Large percolators, often called coffee urns, make coffee for offices, canteens, church halls and community events. Campers like stovetop percolators because they make coffee without electricity.

A percolator or a moka pot

A moka pot is the small pot in two halves that many people call a stovetop espresso maker. The water sits in the bottom half. As it heats, pressure pushes it once up through the coffee and into the top half. A moka pot sends the brewed coffee straight to the top, while a percolator sends it back through the grounds.

The pressure in a moka pot is about 1 to 2 bar. An espresso machine works at about 9 bar.

Moka pots are made of aluminium or stainless steel. Only the stainless steel ones work on an induction hob.

Cleaning and care

After brewing, wet grounds sit in the percolator's basket and need emptying. Paper filters are made for percolators, and they hold the grounds together so they lift out in one go.

A moka pot needs a new rubber seal from time to time. Its filter needs a scrub, and its safety valve needs a check to make sure nothing blocks it. Aluminium moka pots are not dishwasher safe. Owners wash the parts by hand in plain water, without washing-up liquid.

Hot coffee and young children

The Child Accident Prevention Trust says a hot drink can scald a baby even 15 minutes after it was made. It suggests pushing hot drinks, kettles and their cords to the back of the worktop, out of reach.

For a scald, the NHS says to hold the scalded skin under cool running water for 20 minutes, as soon as possible. A scald that is very large or deep, or one on the face, needs 999 or A&E.

Electric percolators and recalls

Makers sometimes recall an appliance or offer a safety repair. The Office for Product Safety and Standards keeps the current list of product recalls for the UK.

Register My Appliance is run by the Association of Manufacturers of Domestic Appliances. Owners register new and older appliances there, so the maker can tell them about any safety repair or recall.

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