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Immersion vs Percolation vs Espresso

September 23, 2017

Coffee is a drink. The drink is made from ground coffee beans. The ground coffee needs to interact with hot water so that the soluble coffee compounds dissolve. That’s about all there is to it.

Except not really.

I’m not going to bore you with the vast, unimaginable, Mariana Trench-like depths there are to coffee beans and I won’t prattle on about the pivotal ‘small print of the small print’ details and minutiae that go in to brewing a fantastic cup.

Here, I just want to explain the three main ways there are to make ground coffee and water interact. Immersion, percolation and espresso. Every method there is comes under this three-pronged umbrella. I think. Let me know if I missed something.

(Technically espresso is a form of percolation, but it distinguishes itself enough to have a separate column.)

a pot of french press coffee brewing

Immersion: the French Press lets the ground coffee and water swirl around while it brews.

a man using a pourover device

Percolation: a man pouring water through a Pour Over device.

spout with espresso pouring from it

Espresso: the machine forces hot, pressurized water through a packed ‘puck’ of ground coffee.


So what’s the difference?

Brewing coffee is all about balances. The key is to obtain an excellent extraction that produces a coffee yield between 18-22% (maximum is about 30%) where the early extracting acids and the later-extracting sugars and bitter compounds are matched evenly which creates a smooth tasting cup. It’s harder than most people think to obtain this balance and is why most people really don’t make good coffee at home.

The yield is changed by five things:

Water Temperature
Brew Time
Grind Size
Grind Consistency
Brew Method (to a lesser extent)

Whether you opt for immersion, percolation or espresso brewing the process is still the same. You are adding hot water and ground coffee together. It’s that the method you choose will dictate how much time is spent brewing which needs to be contrasted with temperature and grind size. You’ll notice the short espresso brew time is compensated with a high temperature and a very fine grind size. So long as the balance is right then it doesn’t matter. The taste can change wildly depending on method but what filter you use that makes the biggest difference.

Espresso is something of an exception purely because it produces an extremely strong and small coffee – the espresso. But you can still approximate brewed coffee from filling your espresso up with hot water and creating an americano.

If you’re looking for something more scientific here’s a great Quora answer that compares the extraction rate between immersion and percolation. The conclusion? Immersion requires a coarser grind to account for the longer brew time.

Sidenote: Grind consistency has a huge impact and is criminally overlooked. You simply can’t get by with a cheap burr grinder or a blade grinder and expect to have an even extraction. This is particularly true of coarser grinds where the cheap grinders throw in lots of fines that majorly overextract and create a bitter coffee. I’d buy preground over these two options with ideally looking to invest (read: $100+) in a quality hand or automatic grinder at some point.

Immersion Percolation Espresso
french press pourover spout with espresso pouring from it
Water is mixed with ground coffee. Water is passed through ground coffee (from gravity). Very hot water is pressurized through ground coffee.
Also called: Infusion, Steeping Drip
Methods: French Press, Clever Dripper, Cold Brew, Turkish Coffee Pour Over, Autodrip Coffee Maker Espresso and to some degree Moka Pot and Aeropress
Brew time: Variable. 4 minutes (French Press) -> 36 Hours (Cold Brew) 3-4 minutes for 16oz brewed coffee Very short – 5-10 seconds for a shot of espresso
Typical Grind Size: Coarse Medium/Fine Fast
Extraction rate: Medium-Slow-Very Slow Fast Very Fast

A few things you should know

Taste

I’ve had numerous conversations about how much these 3 methods affect taste and I’ve never heard a satisfying answer either way.

My personal viewpoint is this. Espresso tastes quite different because it produces a small, strong shot with a small amount of crema on top . It has a very different texture. Immersion and percolation both produce brewed coffee and there is no discernible difference in taste just on this factor. As I mentioned, the type of filter your method uses has a far greater impact on taste ranging from the light and bright Chemex to the full-bodied French Press.

And if you really want to improve the taste of your coffee, get yourself some quality freshly roasted coffee beans.

Don’t choose a method on this

If you’re looking for a way of making coffee then choosing immersion or percolation or espresso is not the way to do it. Immersion alone has at least 5 methods you could choose from and each is appreciably different from the others.

You need to consider your preference in taste, your skill level, your budget and many other things. You need to work out which of the numerous ways of making coffee fits in with your own particular requirements. What you need is a well informed blog article that can give you a clear guide on which method is right for you.

Oh look! I have one right here…

Most Forgiving vs Least Forgiving

Forgiving-ness, a word I maybe just made up, refers to how easy it is to make coffee that doesn’t induce a gag reflex. A very forgiving way of making coffee is relatively simple to make a decent brew. An unforgiving way of making coffee requires expert precision and timing. I didn’t include this in the table as it’s not cut and dry which is which.

Generally speaking, immersion is the most forgiving and espresso is the least forgiving with percolation somewhere in the middle. A long extraction time with coarser coffee gives you a slower brew that is less likely to do bad things to your drink. A short extraction time gives you little time and little room for error.

Trip over in a marathon and it’s no big deal. Trip over when you’re sprinting next to Usain Bolt and you can kiss that medal goodbye.

There are a couple of notable exceptions which I’ll talk about now.

Autodrip coffee Maker. A high quality scaa-certified coffee maker is extremely forgiving. Not because the method is easier, but because it does everything for you. If you like the convenience of old-style coffee makers but are sick of the taste, get yourself one of these badboys.

Turkish coffee. Not something you’re likely to try early on, but one it’s nice to be aware of. Turkish coffee is an immersion method that uses an extremely fine grind and no filter. It’s also hard as nails to get a decent cup. It’s probably easier to just fly to Istanbul – something I recommend.

A big however comes when talking about forgivingness of grind sizes which is a totally different ball game. I explain more in my article on the 4 most forgiving brew methods.

a man pushing down on an aeropress outside

Aeropress. No-one really knows where this little guy fits in. Photo by La Marcozza


Enjoy this article? Absolutely hate it? Either way, let me know in the comments.

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