Using a coffee percolator can be the least favourite method of brewing coffee amongst many coffee fans. Though the sound and the aroma particularly are amazing while the coffee is being made, coffee percolator detractors maintain it’s because all the aromatics in the coffee are going up in the air, vaporized.
You assemble a coffee percolator by putting cold water into a lower chamber in the pot, into which you then insert a hollow metal tube. The tube serves two purposes: it holds a filter basket with the coffee in it suspended above the water, and it provides a conduit for hot water to rise up and reach the ground coffee. You set the coffee basket on top of the tube, and then fill the basket with ground coffee. The tube usually comes up through the centre of the basket. You then put the lid on the coffee pot, and heat the water.
Some models you place on the stove top, and a stove burner provides the heat. Others are electrical and have a heating element built-in under the water chamber. As the water comes to boiling temperature, steam pressure forces it up through the tube. Some machines keep the water under the boiling point deliberately, because it’s only with boiling water that some of the bitter compounds in the coffee start to come out.
Many models have glass lids or small glass domes at the top that let you watch the coffee perk up through the tube. Some coffee percolators are even made entirely of glass, to reveal all the action. The water perking up hits the top of the coffee pot, and falls down on the cover of the basket, which has holes in it. It drizzles down through the coffee, then down out through the perforated bottom of the basket back into the water chamber part, and starts its cycle over again. Thus, the infused water passes through the coffee again and again.
To coffee percolator detractors, this is the root of all the problems with it: they say that the ground coffee gets “overextracted” or “over-leeched”, drawing bitterness out, and that water which is already infused with coffee gets boiled, burning and oxidizing the flavours.
It can take a while to make a pot of perked coffee, up to 20 minutes for 6 cups of coffee. When done, you remove the lid, remove the basket and the metal tube, put the lid back on, and serve.
Some electrical models have lights on them that light up when they’re done, and others that even turn themselves off when they sense the water reaching a certain temperature.
In the “old days”, people used to use the stove-top percolator models to reheat coffee constantly through the day, and produce what people now think of as bitter sludge that had an unpleasant caramelized taste.
Use coarse-grind coffee. This may help prevent somewhat the water over-extracting from the coffee.
The old aluminum stove-top ones (or even electric ones) make great asparagus steamers (provided you don’t use the pots for coffee anymore.)
The percolating method for coffee was invented in France in 1827. It had its heyday in North America in the 1950s.
“Percolate” refers to the hot water drizzling down through the ground coffee.