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Percolation versus immersion: two families of brewing methods

There are dozens of coffee brewing methods: pour over, French press, AeroPress, moka, espresso, cold brew and many others. They may seem chaotic and overwhelming, but in reality they all come down to two fundamental families: percolation and immersion. This distinction orders the whole world of coffee brewing. Percolation is the methods in which water flows through the coffee (like pour over), and immersion is the methods in which coffee steeps in water (like French press). Each family gives a different flavour and character of the brew. In this post you will get to know both families, learn how they differ, how they affect flavour and which to choose. It is a journey that will order your understanding of coffee brewing. Let us start with why it is worth thinking of methods in terms of two families.

Two families of brewing methods

The multitude of coffee brewing methods can be overwhelming, but they all fall into two fundamental categories: percolation and immersion. This distinction is the key to understanding how coffee is brewed at all. Percolation refers to when fresh water passes through coffee, extracting its flavour (as in pour over). Immersion refers to when coffee steeps in water that gradually becomes more and more saturated with coffee (as in French press). In other words, in percolation water is in constant motion through the coffee, and in immersion coffee and water simply rest together for a set time. Almost every brewing method belongs to one of these two families (or combines both). Understanding this division orders the whole world of brewing: instead of remembering dozens of methods, it is enough to understand two principles. It is the foundation of conscious coffee brewing. So let us get to know each family separately, starting with percolation.

Percolation - water flows

Percolation is the family of methods in which water flows through a bed of coffee, extracting flavour as it flows. Water flows through a bed of ground coffee, extracting it as it goes, in a controlled flow that defines pour over, espresso and drip coffee. To the percolation family thus belong: pour over (V60, Chemex), espresso, drip machines and moka. The key trait is the constant motion of water: fresh water constantly contacts the coffee, and coffee-saturated water flows away. It is a dynamic process. In percolation extraction happens dynamically, because the water constantly changes as it moves through the coffee bed - pure water at the top dissolves acids and aromatics first. Percolation usually gives a cleaner, clearer brew, because the water flows through and is filtered (often by a paper filter holding back oils and fine particles). It is a method for those who value precision and cleanliness. Percolation is the dynamic flow of water through coffee, giving a light, nuanced flavour. It is one of the two great families of brewing. We write more about this method in our post on pour over V60 and Chemex.

Immersion - coffee steeps

Immersion is the second great family of methods, in which coffee is completely submerged in water for a set time. Immersion means the ground coffee is fully submerged in water for a set period, in a steep and separate process where water and coffee mingle freely. To the immersion family belong: French press, cold brew, and partly also AeroPress (which combines immersion with light pressure). The key trait is the lack of flow: coffee and water rest together, and extraction happens slowly as the water saturates with coffee. After a set time the brew separates from the grounds (by a plunger, filter or pouring off). Immersion usually gives a fuller, more intense and textured brew. Importantly, some immersion methods, like French press, do not use a paper filter, only a metal plunger, so they retain all the coffee oils in the final cup, which makes immersion brews richer, fuller and more textured, with an intense, bold flavour. Immersion is the calm steeping of coffee, giving a rich, full brew. It is the second of the great families of brewing. We write more about it in our post on French press.

How the family affects flavour

The choice of method family directly shapes the flavour of coffee. Percolation, thanks to the constant flow of fresh water and frequent filtering (especially paper), gives brews that are cleaner, lighter and more nuanced, showing off subtle aromas and acidity. For those who prefer a lighter, more complex flavour, percolation beckons. Immersion in turn, thanks to long, static contact of coffee with water and often the lack of a paper filter, gives brews that are fuller, more textured and intense, retaining the coffee oils. If you lean towards bold, intense flavours, immersion may be your choice. It is a simplification, but it captures the essence: percolation is cleanliness and finesse, immersion is body and intensity. Of course much depends on the particular method, the grind and the parameters, but the family gives the basic character. Understanding how the family affects flavour lets you consciously match the method to your preferences. It is the key to brewing the coffee we like. The choice of family is a choice of the flavour profile of the brew.

Filter and oils

An important aspect differentiating the families is the role of the filter and coffee oils. In percolation a paper filter is often used (as in V60 or Chemex), which holds back not only fine particles of coffee, but also oils and some compounds, giving a very clean, clear and light brew. That is why coffee from a pour over is so transparent and nuanced. In immersion, especially in French press, a metal filter (plunger) is used, which lets the coffee oils and fine particles through into the final cup. These oils give the brew richness, body and texture, but also a slight cloudiness and sediment. That is why coffee from a French press is fuller and more textured than from a pour over. The type of filter is thus a key factor differentiating flavour: paper gives cleanliness, metal gives body. The AeroPress is an interesting intermediate case, combining immersion with a paper filter, which gives a brew at once full and clean. The filter and oils are the concrete mechanism by which the method family affects flavour. It is the physical explanation of the difference between cleanliness and richness of the brew.

Which family to choose

The choice between percolation and immersion depends on your flavour preferences and lifestyle. Choose percolation (pour over) if you value a clean, clear, nuanced brew, showing off the subtle aromas and acidity of the coffee - it is a great choice for specialty coffees of interesting notes. It requires, however, a little more attention, technique and equipment. Choose immersion (French press) if you prefer a full, rich, intense brew with body and texture, and at the same time value simplicity - the French press is forgiving and easy to operate. Cold brew, also immersion, is an option for summer and for sensitive stomachs. There is no single better family - there is only the one better for you, your taste and situation. Many coffee lovers use both, depending on mood and coffee. It is worth trying both families and comparing, to develop your own preferences. The best way is to experiment: brew the same coffee by pour over and in a French press, to feel the difference. Which family to choose? The one that gives the brew you love. It is a matter of taste, not rules.

Two families in a table

Let us set both families of brewing methods side by side:

The table shows that percolation and immersion are two fundamentally different approaches. Percolation is the dynamic flow of water through coffee, often with a paper filter, giving a clean, light brew. Immersion is the static steeping of coffee, often with a metal filter, giving a full, rich brew. Almost every method belongs to one of these families. Understanding this division orders the whole world of coffee brewing. They are two great philosophies of extraction, each of its own character.

Why it is worth knowing this

Understanding the division into percolation and immersion enriches conscious coffee brewing. First, it orders the chaos of methods: instead of remembering dozens of techniques, it is enough to understand two fundamental principles. Second, it helps predict flavour: knowing whether a method is percolation or immersion, you can expect a clean or full brew. Third, it eases the choice of method to your preferences and situation. Fourth, it deepens the understanding of why the same coffee tastes different from a pour over and from a French press. Fifth, it is fundamental knowledge on which you can build further learning about brewing. A conscious coffee lover knows that behind the diversity of methods stand two simple families. Next time, choosing a brewing method, it is worth thinking about whether you want percolation or immersion - and what brew you are looking for. It is knowledge that orders and deepens the relationship with coffee. The two families are a map of the whole world of brewing. It is the key to a conscious choice.

The key points in a nutshell

All coffee brewing methods fall into two fundamental families. Percolation is the methods in which water flows through a bed of coffee, extracting it dynamically - here belong pour over (V60, Chemex), espresso, moka and drip coffee. It gives a cleaner, lighter and more nuanced brew, especially with a paper filter. Immersion is the methods in which coffee steeps in water for a set time - here belong French press and cold brew. It gives a fuller, richer and more textured brew, especially with a metal filter that retains the oils. The choice of family is a choice between cleanliness and body. There is no better one - there is the one better for you. Want to compare brewing methods and record your impressions? Keep tasting notes in the GustoNote app. See also our posts on coffee brewing methods and on pour over V60 and Chemex.