Over Extracted Coffee (What Is It And How To Avoid It)


When you want the perfect cup of coffee, it can seem horrible if the coffee comes out wrong. You make sure that you have quality coffee beans roasted, and it smells fantastic while it brews, but when you take a sip, it doesn’t taste very nice. What went wrong with the cup of coffee?

An over-extraction occurs when you remove an excessive amount of the soluble flavorings from the coffee bean. Because of the high level of extraction, the flavors are unpalatable and can taste bitter.

Over-extracted coffee sounds intimidating, but it’s not too difficult to avoid once you know what the problem is. This article addresses different levels of extraction, different ways it can go wrong, and how to achieve the perfect level to make your perfect cup of coffee.

What Causes Over Extracted Coffee?

Just under 30% of the average coffee bean is water-soluble. This means that almost thirty percent of the coffee bean can be dissolved into your cup, depending on how you brew it. 

However, not all of that thirty percent tastes good, so we aim for a little lower than that. 

Over extraction, which is what happens when too much of the coffee bean is dissolved in our cup, will be discussed further along in this article.

When hot water (used for the most common brewing methods) runs through ground coffee beans, the parts of the bean that can dissolve into the water do just that. 

This is extraction. Specifically, the flavoring and compounds are being extracted from the bean and into the water. What you get is coffee. 

Hotter water, longer brewing times, and other factors can increase the amount of coffee bean that ends up in your coffee.

Coffee extraction will not remove the solid parts of a coffee bean, so you don’t need to worry about hitting the sweet spot by extracting the coffee to the point the grounds disappear entirely. 

If they end up all in your cup, you should be able to see the grounds still intact in your coffee.

How Does Extraction Affect Taste?

Different compounds have different heat temperatures or times at which they dissolve into water. 

This is relevant in extraction because the coffee bean isn’t just one compound. 

All the different flavors, fats, antioxidants, and other compounds in the coffee bean are extracted at different times and at different rates. 

These things all have different tastes, so brewing in a way that over or under extracts the coffee can cause huge differences in the flavor of your cup of coffee.

How Do You Extract The Perfect coffee?

The perfect extraction level allows for the best flavors of the coffee to make their way into your cup without allowing the bitter flavors of over extraction to overwhelm your coffee. 

You should taste all the good flavor notes of your particular roast. It shouldn’t taste like cheap, supermarket coffee or like coffee that’s remained in the pot for a bit too long.

To achieve the perfect level of extraction, you’ll want to make sure you follow all timing and consistency recommendations for your preferred brewing method. 

This will let you taste the richness of the coffee and the balance of acidity and finish.

How Do You Tell If Coffee Is Under Extracted?

Just as coffee can be over extracted, it can also be under extracted. In general, this means that the heat in the water was too cool, or that the water wasn’t applied to the coffee beans for enough time. 

The result is under-extracted coffee, which is where only the first flavors have come out of the coffee grounds and into your coffee.

There are a few ways you can tell if coffee is under extracted. The best way to check extraction level (unfortunately, in the cases of poor extraction) is to taste the coffee.  The following are ways you can taste under extraction.

The Coffee Is Sour

If the coffee is sour, it might be under extracted. This sour taste isn’t quite the same as bitter, and it’s not the same as acidic, though all these taste profiles are described similarly. 

Sour, in this context, is the taste that makes you screw up your face or stick out your tongue.

The coffee tastes sour because the acids in coffee are one of the first things extracted.  This means that sourness is one of the strongest flavors in under-extracted coffee.

The Coffee is Thin

Essentially, under extraction leaves coffee too watery, without enough of the coffee compounds present. 

You can taste this in under-extracted coffee. It tastes like there’s not enough coffee in the water, because that’s exactly what’s happening!

The Coffee is Salty

Another of the first compounds to extract from coffee is salt. Under-extracted coffee doesn’t quite taste like you poured salt into it, but salt is way more present a flavor than it is in a balanced cup of coffee. 

If your coffee tastes notably salty, this is another hint that it might be under extracted.

What Are The Signs of Ideal Extraction?

If your coffee is perfectly extracted, no single note should overpower any others. 

You should be able to taste a bit of bright acidity, as well as the more chocolatey notes. 

There should be plenty of flavor, but the flavor shouldn’t be overwhelming in a bad way.

There should be plenty of coffee compounds in your drink, but there shouldn’t be so much that you can feel it in your mouth.

What Does Over Extracted Coffee Taste Like?

Over-extracted coffee has too much coffee compound in the drink. When coffee is over-extracted, the water has extracted most of the soluble content from the coffee grounds. This includes flavors we really don’t want much of in our coffee.

The Coffee Is Bitter

One of the biggest clues that your coffee has been over-extracted is that the coffee is bitter and not just a little bitter. 

Some bitterness is fine; think bittersweet chocolate and the depth that the bitterness adds. 

When that bitterness is overwhelming, then either your coffee was over-extracted or your beans were roasted too long. 

It’s much easier to fix your next cup of coffee if it’s just a matter of over-extraction!

The Coffee Tastes Dull

Over-extracted coffee will taste dull. The excess of flavors and their lack of balance combine to make a coffee that gives the same dull taste as dirt. 

It’s not a lack of flavor so much as flavors that cancel each other out and muddy the palate.

The Coffee Feels Dry

This quality of over-extracted coffee is the weirdest, but it’s also the most memorable and easiest to spot. 

Have you ever had a sip of coffee, only to immediately check your cup to make sure there aren’t coffee grounds in it? 

When your coffee makes your mouth feel dry and sandpapery without necessarily having any visible particles, that would explain the sensation. This is over-extracted coffee.

What Causes Coffee to Be Over Extracted?

There are a few things that can cause coffee to become over extracted. They all come back to the same concept; too much of the coffee beans made their way into the coffee. 

There are multiple ways this can happen, and knowing what they are is the best way to avoid having it happen to you. 

If you want to achieve the perfect cup of coffee, watch out for the pitfalls below.

Water Temperature

The hotter the water is, the more quickly it extracts water-soluble compounds. 

This includes all the parts of coffee that we’ve talked about. Water for brewing coffee should generally be about 200 degrees Fahrenheit (93 degrees Celsius). 

A higher temperature than this and the coffee will be over extracted. Much below this, and the coffee will be under extracted.

Brewing Time

Brewing time plays a big part in how extracted coffee gets, especially in brewing methods for which the coffee grounds stay in contact with the water for some time instead of the water simply moving through it. 

The water needs to be in contact with the coffee grounds for long enough to get a good coffee, but not so long that it dissolves all of the beans’ compounds into your drink. 

For brewing time, be sure to refer to your user manual or to guides for your preferred brewing method since this varies widely.

Consistency

The consistency of your coffee grounds is the last really common factor for over extraction. 

If your coffee beans aren’t ground enough (or at all!), then the water has a harder time accessing the soluble compounds. 

This translates to less coffee in your drink or under extracted coffee. If your coffee beans are ground too finely, on the other hand, then the water can absorb more than usual, and it can do it faster than usual. 

If your coffee is still ending up over extracted even when you’re sure you’ve got the water temperature and brewing times right, check to make sure that your coffee grounds aren’t too fine.  They should have a little bit of substance to them.

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