How Does a Coffee Percolator Work?

There’s nothing quite as delicious as the smell of fresh coffee brewing in the morning, the flavor wafting through the whole house and the sound of the percolator rumbling on the stove. So how does a coffee percolator work?

A coffee percolator is split into two chambers; you pour water into the lower chamber and add the course ground coffee beans into the upper part.

A coffee percolator works by using heat to drive water up from the lower chamber via a vertical tube and over the coffee beans.

The water filters through the coffee beans and flows back into the lower chamber for the cycle to be repeated.

This method of coffee brewing has been around for a long time and aimed to improve on the decoction brewing technique, or in regular english: the act of simply boiling water with coffee grounds mixed in.

To “percolate” literally means to filter through or to become spirited, lively. This remind me of the bubbling you see inside the glass top of some manual percolators.

The History of Coffee Percolators

The coffee percolator dates back to 1810!

It is purported to have been invented by Count Rumford, otherwise known as Sir Benjamin Thompson. He didn’t like alcohol or tea, so instead decided to promote coffee as his beverage of choice for its stimulating benefits.

The first commercially available percolator was around in 1819, incorporating features to enable home use on a kitchen stove.

The Brewing Process

A percolator consists of a coffee pot with a small compartment at the bottom that is placed closest to the heat source.

A tube leads upwards from the lower compartment to the top of the percolator. Just below the upper end of the tube is a perforated compartment.

Depending on the amount of cups needed, water is poured into the low compartment of the pot and coarse ground coffee into the top chamber.

It’s important that the water level is below the bottom of the coffee compartment.

The water is heated and as it begins to bubble, the water is pushed up the tube.

From the top of the tube, the water flows out and over the lid of the coffee compartment.

Perforations in the lid distribute the water evenly over the coffee grounds.

The water then seeps through the grounds and back down into the bottom of the coffee compartment.

As the brew continually seeps through the coffee grounds, the temperature of the liquid approaches boiling point and the perking or spurting sound stops.

The coffee is then ready to drink!

Coffee Percolators

Coffee percolators are a very simple and inexpensive way for you to brew coffee.

They used to be very popular in the early 1970s until the automatic drip coffee machines appeared and stole their market share.

One drawback of coffee percolators is their tendency to over-expose the coffee grind to higher temperatures than other brewing methods.

Also, coffee percolators can sometimes re-circulate already brewed coffee, causing the coffee beans to be over-extracted and lacking flavor with a somewhat hollow taste.

With a manual percolator it’s important to keep an eye on the heat level otherwise the coffee can become bitter.

These days some models of percolator have an integral electric heating element which automatically reduces the heat at the end of the brewing phase.