At the Famous Brands Coffee Company, we often get asked if we sell coffee percolators and the answer is that these went out of fashion 40 years ago, but the name has stuck around and is as synonymous with coffee making as “Hoover” is to vacuum cleaners and “Xerox” is to copiers.
What made the coffee percolator unique was the fact that water would be heated, pass up a tube and be released above ground coffee held in a porous metal basket. The resultant hot water and coffee extracted would then fall back into the water reservoir at the bottom of the percolator and the process would repeat itself. For this, we go back to 1819 and have Parisian metalworker, Joseph-Henry-Marie Laurens to thank.
The advantage was that the process ran itself after applying heat, which was typically a heating plate inside the percolator, but the disadvantage, and quite a serious one at that, was that the coffee could not only get stronger with each pass of water, but over-extracted too. There were also issues with fine coffee grounds “leaking” out of the metal basket back into the coffee and while this was later solved by pre-packing ground coffee into doughnut looking filter paper packets, the variability in taste and over-extraction still remained.
The answer was the moka pot which differed from the percolator in two very critical ways. Firstly, while water was heated in the base of the coffee maker as for the percolator, this time it passed through the coffee ground basket on the way up the tube and the extracted coffee then continued to rise until it emptied into a storage chamber separated from the water below. This meant that there was no continual recirculation of water with extracted coffee through the coffee grounds as for the percolator design. An innovative solution from 1933 that we have Alfonso Bialetti to thank for, but that is not the end of the difference because the other major difference was that this approach saw coffee extraction occur under pressure.
Source:Alborzagros – Own work, CC BY-SA 3.0,https://commons.wikimedia.org/w/index.php?curid=31410856
The heating up of the water in the lower chamber of the moka pot created pressure in the chamber that then pushed down on the water, and forced it up the tube, as it did in the percolator. However this time the water didn’t flow out of the tube at the top and fall on top of the ground coffee as it did in the percolator but was forced through the coffee grounds on the way up! This required far more pressure and so the moka pot was designed to handle this increased pressure. This was the birth of modern espresso making … bless that man!
Filter Coffee Machines
Somewhat closer to the coffee percolator comes the “filter coffee” machine or, as it is often called, the “drip coffee” machine. Here water is again heated in a chamber and then pumped up to fall ontop of the ground coffee, as in a percolator. However this time, the hot water passes through the coffee only once and falls or “drips” by gravity into a flask underneath the coffee. The drawback of the percolator, over-extracted coffee, is thus avoided. In this approach, the ground coffee itself is held in place in a filter paper cone that allows water out but retains all the coffee solids.
The filter coffee maker has remained popular for over a century now and is still a mainstay in busy areas such as conference venues or larger offices. It is a relatively inexpensive machine to buy and operate, and it can make a flask of coffee, enough for 10-12 cups, in under 8 minutes.
So there you have it, the differences between a coffee percolator, a filter coffee machine and a moka pot. Hopefully, this will help you in approaching suppliers to ask for the coffee maker that you really want.