As you might imagine, there are many and varied coffee extraction methods, some of which are even viewed with mild distrust.

Today we’re going to talk about the three more common and popular extraction techniques, some which have important histories: immersion/infusion, percolation and pressure.

It’s important to understand that coffee extraction methods, whether ancient or some quite modern, are all now utilized with care and dedication, not to mention millimetric precision and cutting-edge techniques.

Whether you are an espresso coffee lover, or a staunch supporter of the moka, there are some well-known techniques and methods that you absolutely must be aware of in order to broaden your world view of coffee. These can be divided into three families:

The immersion/infusion method

This is the most traditional method and also the easiest to put into practice, as it is far more forgiving: you just need a little imagination and a lot of patience.

The technique is quite simple: the coffee is left to soak (in water, obviously) for a certain period of time and then it is filtered, even if not always.

Infusion is an ancient method originating in the Middle East and is one of the cornerstones of traditional Arab and Turkish coffee. The preparation itself is also simple: it requires hot water and two tablespoons of ground coffee, usually left to boil twice. In infusion coffee there is normally no filtering mechanism: it is a coffee that should be drunk and savoured slowly, being careful not to tilt the cup too much once it has been poured.

The Arab method, on the other hand, is more widespread and slightly more complex: it is derived from traditional Ethiopian ceremonies and involves the use of a coffee pot with a long, narrow beak. Naturally, the longer the coffee is left to infuse, the more intense and full-bodied the flavour becomes.

For this reason it is recommended not to exceed 4 minutes of infusion so as not to extract more than is necessary into the cup.

Interestingly, the principle of infusion is also the basis of cupping, which is not an extraction method very well known to the public but is an industry-standard tasting protocol utilized to evaluate the quality of a coffee.

The percolation method

In this method, the ground coffee is usually exposed to an amount of (almost) boiling water (95 degrees) relative to the dose of coffee used and the quantity to be extracted into the cup.

The water is poured directly over the ground coffee which, due to the natural “pressure” of gravity, will extract the soluble solids it encounters along the way.

There are several aspects which will influence the final result.

First of all, the filter used to hold the insoluble part, as well as to separate it from the liquid, can be made of metal, fabric or paper. The result will depend on the filtering property of these materials. Generally, it will be fuller and denser with a metal filter, like the Neapolitan, while more delicate and complex with a paper filter, like the V60.

Another important element will be the shape of the filter which can be flat, conical or concave. Here, the kinetic energy exerted by the water upon the ground coffee, due to the friction generated by the particular type of filter, will vary.

Finding the right balance is fundamental such that it avoids allowing the water to flow too quickly (causing under-extraction) or significantly obstructs the liquid’s flow path (creating over-extraction), thus obtaining a correct extraction, which normally takes place in 3 minutes.

The pressure method

Here the difference is significant, since the water is forced through a system that compresses the passage of the water. A higher extraction capacity is therefore generated which makes it possible to dissolve the ground coffee in less time and at lower temperatures.

It is the principle that allows you to obtain an espresso in a few seconds and here the resistance exerted by the ground coffee is even more important, 9 atmospheres of pressure exerted by the machine, allowing for a homogeneous extraction.

Another well-known pressure method is that of the moka, where, however, the force exerted is much lower, and as such no compression of the ground coffee is necessary. Here the extraction time ranges from 2 to 3 minutes and will greatly depend on the dose of coffee and the amount of water used.