Under Extraction is ruining your coffee - Tips on how to fix it!

3 min read 3 Comments

Under Extraction is ruining your coffee - Tips on how to fix it!

Understanding Under Extraction

On the surface the process of coffee brewing seems simple. But as with most things — once you get into the thick of it, the details provide a far more nuanced and complex picture.

And with coffee, it turns out to be more than just coffee grounds being dissolved in hot water.

Sure, this is the essence of the “extraction” process — or rather, the process of extracting flavor from your coffee beans.

However, if you want to make sure that you get the taste just right — you need to think about the science which fuels the process.

There are countless factors that determine how your coffee will taste — the time period during which your coffee is in contact with water, the water’s temperature, the coffee roast, the water-to-coffee ratio; the list goes on and on.

So, why should all these details concern you?

Well, if you feel like your coffee isn’t as great as it could be, or that the taste is just a bit off; you’ll find that learning more about the entire extraction process will lead to a more enjoyable taste!


What Is Under-Extraction?

Simply, under extraction occurs when we don’t ‘pull’ enough flavour out of the ground coffee.

It’s akin to under baking a cake.

We haven’t given the water enough ‘contact time’ to extract the oils from the coffee.


Under Extracted Coffee on the left has a straw colour.

Identifying Under-Extraction.

Balance is the key to all things taste.

The perfect harmony of sweetness, acidity & strength is the holy grail for coffee brewing.

If these elements are out of whack, it doesn’t -necessarily- mean that the coffee is ‘bad’ after all a low acidity coffee can be dynamite through milk, and a high acidity coffee can be life changing and highly desirable as a Pour-Over.

It’s when we don’t want these flavours that our experience turns from elation to anger.

Under Extraction is perhaps the worst of our brewing errors.

You can expect sour, salty, thin, boring, and dull coffee.

Sour being the most identifiable flavour in under extracted coffee.


The Water’s Role In Under-Extraction

Any coffee-based drink involves two things — water, and ground coffee. Why is water so crucial? Well, and this isn’t exclusive to coffee — water is one of the most amazing solvents in nature.

In fact, it’s probably the most universally useful one, at least when it comes to human use.

Water’s molecular structure ensures that it’s incredibly attractive to a wide variety of molecules; when you translate that to our level of interaction with nature, it means that things dissolve in water easily.

And if you heat up that same water, its molecules are even more agile — which brings us to brewing.



How Does Under Extraction Happen?

Two main reasons-

  • Your brewing water is not hot enough.

Cold or Colder water extracts at a slower rate than hot water.

That’s why it takes 12-24hrs for Cold Brew to fully brew.

Perfect espresso machine brewing temperature is 93-96c.

Cold brewed espresso coffees have lower bodies, lower sweetness and enhanced acidity. 

These unwanted flavours aren’t just tasted in espresso brewed coffee, but in all brewing types.

Top Tip-

‘Flush’ your espresso machine head to heat it up before pulling a shot.

Also, preheat all your brewing devices with boiling hot water before brewing to get them up to temp - a cold plunger will steal all of your brewing heat!

  • Your brewing time is too fast.

Again, its contact time that is the hero here.

You need to brew longer.

Espresso extraction time generally should be around 25-30sec.

With Plungers being 4-6min and Pour-Overs brewing in around 3min.

These will vary from machine to machine and the coffee type and roast level, but those times should get you in the ballpark.


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How to slow down your shot or Pour- Over time?

Grind finer!

The grinder is your friend.

Simply, set the grinder ever so slightly finer.

I can’t stress this enough that it could just be the tiniest change of the grinder that gets you the desirable result.

Go too far and you’ll have 40 second plus shots and you’ll have to change the grinder again.




As coffee brewers, under-extraction is part and parcel of getting your coffee just right.

It’s not something to be concerned about and the fixes are very simple.

There’s also a tremendous amount of satisfaction when your fix your brew and get it Goldilocks- just right!



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3 Responses


April 07, 2023

For many years I have successfully made coffee via the stove-top method. Of late I am finding it difficult to get consistency. You don’t mention stove-top in your Blog. I have tried virtually all the points you suggest, but perhaps it’s my taste bud thats are failing! Your coffees are probably the best I have found recently. Still not sure which one I like best

Kind regards,


Peter Heffernan
Peter Heffernan

April 07, 2023

Worth taking the time to read. Proper extraction and my favourite Fox coffee gives me a cup I love.


June 22, 2021

Some great tips. Many thanks

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