10 Reasons You Have Sour Coffee And How To Fix Them

A pretty woman with red hair looking at her coffee cup in a bad way since she has sour coffee

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It’s a rainy day, and you’re about to enjoy that cup of coffee you just brewed. You take your first sip- and it tastes sour. Not a little bit either, but a really, really sour taste. What do you do? In this article, I will explain how to fix the problem with a few easy steps!

1. Under Extraction-Over or under extraction will make your coffee taste sour.

Reason: Under extraction could be due to old or low-quality coffee beans, the coffee ground is too fine for what you need, or it’s not ground at all.

Over extraction can happen when you’re using an automatic drip machine, and your coffee grounds are in contact with water for too long (or if you use a French press). This will make your coffee taste sour.

Steps: To fix under extraction, change the grind size of your beans to be more coarse and use half the amount called for in your recipe or if using an automatic drip machine, change settings to brew shorter.

For over-extraction, you can try adding some cold water to cool off your brewing temperature or pour away some of the brew before it gets over-extracted.

Tips: If you’re using a French press and the coffee doesn’t have a sour taste but a bitter taste to your taste buds- try adding more cold water to your filter or change grind size coarseness from “course” to “medium.”

2. Under Roasted Beans

Reason: Under roasting, beans will result in sour coffee.

Steps: To fix under roasted beans, you’ll need to roast the bean longer for a darker color and richer flavor- but don’t exceed your desired level of darkness!

Speak with your local coffee roaster to find your sweet spot. If your coffee tastes weak, then dark roasts are more your preference.

Tips: If you’re using an automatic drip machine with unroasted or light-roasted beans, try using a coarser grind size(especially if you’re not getting the results you want) or change to dark roasts.

3. Stale Coffee Beans

Reason: Stale beans will result in sour coffee.

Steps: To fix stale beans, buy new ones!

Tips: Make sure you buy enough coffee beans that you have enough to sustain your habit but not so much that they are becoming stale before you use them.

Also, store them in an airtight container that is meant for coffee beans.

4.Your beans are ground too coarsely

Reason: Grind size, which is too coarse, will result in sour coffee with a bitter taste.

Steps: To fix this, grind your beans more finely!

Tips: The best way to grind your beans is to start with a medium grind size and adjust the coarseness to your desired preference.

You can also try using a burr grinder which will give you more consistent results than blade grinders. Stone mills are another good option, but they cost significantly more than other coffee bean grinders.

Related article: The best Espresso grind size

a barista timing the brew of a pour-over to make sure a short brew time doesn't make her coffee taste sour

5.Your brew time was too short

Reason: If you don’t brew for the right amount of time, you will make under-extracted coffee, and your coffee will taste sour.

Steps: To fix this problem, try brewing coffee longer or using a coarser grind size; it may not give you quite as tasty results, but it’ll keep that sour coffee flavor away!

Tips: The most important thing to remember when brewing is to make sure the water is properly heated.

If your water isn’t hot enough, it won’t dissolve all of the coffee flavors from your brew- which means you’ll be left with a not-so-tasty cup of sour coffee!

6.You didn’t use enough water

Reason: If you don’t use enough water, your coffee will taste sour.

Steps: To fix this problem, make sure to add more water!

The ratio of coffee grounds to water should always be about two tablespoons per six ounces of liquid- but if it tastes too weak or strong for your liking (or is completely off of your desired taste), try adjusting the grind size to be more coarse or experiment with different brew times.

Tips: If you’re using an automatic drip machine, it’s usually best to use a medium-coarse grind size as this will ensure that all of the beans are saturated in water, and your coffee grounds won’t be sitting on top of dry ones.

7.Ultra-Fresh Beans 

Reason: Very fresh beans will make your coffee taste sour

Steps: If the beans are too fresh (normally 3 to 5 days after freshly roasting ), they haven’t had the proper amount of time to de-gas and will still have carbon dioxide trapped in them.

Tips: Don’t use beans that are a week or less from their roasting date. This will make watery sour coffee.

8.Taste Preferences

Everyone has different taste preferences, and some will think that a sour coffee is perfect, while others may find it unpleasant.

Some people like bitter coffee, sour coffee (also known as hipster coffee) Tart coffee.

All of these are acceptable to some people. The problem is that some sour coffee characteristics are due to mistakes in the brewing process, and it is important to know the difference.

Tips: If you’re not sure whether the sour taste is just the right amount of tartness for you, try adding some sugar to see if that helps! It will make your coffee taste sweeter and mask any bitter coffee flavors in your drink which could be throwing off how acidic it tastes.

Top view of an empty coffee cup with coffee stains on the bottom and an empty dirty Moka pot after finishing drinking. A dirty Cup and a Turk on a bamboo stand can cause a sour-tasting coffee if not cleaned properly


It might not seem necessary to clean your machine every time. Can you get away with just rinsing the carafe?

This will suffice most of the time, but you do need to clean your water reservoir, grinder, and filters once a week.

Depending on the type of machine you have, it will tell you when to do a cleaning or clean itself automatically.

My Breville Oracle, for example, needs a cleaning tablet and tells me to clean it every 80 shots or so.

How to Fix It: Make sure to keep up with the maintenance of your equipment by cleaning, descaling, and wiping down any area that comes into contact with water, grounds, or coffee.


No doubt you have been with your coffee pot through the good times and the bad. But, unfortunately, like people, machines aren’t immune to the effects of aging.

When your equipment begins to malfunction, you don’t have much choice but to fix it or replace it. Unfortunately, it isn’t worth fixing it a lot of times since the price will almost match what a new model would cost you.

It is probably time to purchase a new coffee maker or grinder.

Related articles:

Coffee machines with a built-in grinder

Best 4 cup coffee makers

Best coffee machines under $100

If you notice a sudden change in the quality of your coffee and you haven’t changed your beans or coffee brewing process, this is a red flag that your equipment is starting to fail.

How do you get rid of the sour taste of coffee?

1. Grind Finer

If your grind size is finer, it will help take away the bitter taste since the beans are in contact with the water for a shorter time.

2. Increase the Brew Time

Increasing the brew time will also help take away the sour coffee taste, but it will make your coffee more watery. You can fix this by using a finer grind size and adding more coffee.

3. Raise the Coffee: Water Ratio

Increasing the coffee to water ratio will decrease the bitterness by increasing the amount of coffee. You can make your cup stronger by using a finer grind size and more coffee beans, but this will increase the sour coffee taste because it increases the contact time with water.

A happy medium between these two fixes might be to use a coarser grind and reduce your brew time. This could help both problems without making one worse than before!

4.Check your water temperature 

Your water temperature might be too high. The ideal coffee brewing temp is between 195-205 degrees Fahrenheit, and when the coffee touches, it will cool down to 185 degrees.

If you’re experiencing sour-tasting coffee, this could be why!

Depending on the Coffee brewing method, here are some tips to fix sour coffee

A set of French press coffee cups and plunger

Dilemma: French Press is sour

Resolution 1: Extend the brew time for more extraction

Serve the coffee after it has been brewed for at least four minutes.

It is possible to brew even longer than this (we have found some coffees that make perfect French presses after just six minutes), but eventually, you will end up with a bitter flavor.

French presses are prone to over-extracting coffee, so decanting might be a good idea if you still have another cup(s) when you’ve finished filling yours. 

Resolution 2: Set your grinder to a setting that will grind finer.

Too fine a grind is likely to clog the cheesecloth, or worse, leave your coffee cup filled with mud from the particles the mesh filter does not capture.

You will need to experiment a few times until you find a grind that is just the right size, making the beans fine enough for balanced coffee but still coarse enough so that you don’t end up chewing your morning brew.

Resolution 3: Try a different type of coffee.

Some French press fans prefer dark roast coffee(espresso roast) since it emphasizes the bitterness of both types.

If you use a light roast and coarse grind, there is a chance that the flavor of sourness will be more pronounced.

Unlike the many varieties at the grocery store, your coffee roaster might be able to recommend specific blends for your specific preference.

Related articles:

Lifeboost coffee review

Best espresso

Strongest coffee

Dilemma: Cold Brew Is Sour

picture of a black Bialetti Moka pot with two cold brew coffee cups in front of it

Resolution 1: Grind your beans finer

Making cold brew coffee is very similar to using a French press. However, the coffees are steeped for an extended period of time, which often eliminates many problems when making hot brewed coffee.

However, if you have a sour cold brew coffee, the grind is likely way too fine.

Resolution 2: Increase the coffee-to-water ratio.

There might be a problem with the amount of coffee grounds you are using.

Typically, for cold brew, you should have a grounds-to-water ratio of 1:5 to 1:4. This is a weight-based calculation, not a volumetric calculation.

Find out which coffee scale is best for you by checking out our review of the best coffee scales.

Dilemma: Pour Over/Drip Coffee Is Sour

a Chemex cold brew coffee maker with life boost coffee and the box

Resolution 1: Grind your beans finer

Using too coarse of a grind may lead to sour drip coffee. Pour-over coffee can also taste sour due to this.

When the flavor is balanced, you know you got a perfect extraction, so grind finely until you achieve that.

Additionally, finer grinding slows down the drawdown (the time it takes for coffee to drain from the filter into the carafe), which means two ways to increase extraction.

The grind should be sneaked up on carefully(meaning you should do it gradually)

Resolution 2: Increase your brew time.

Pour overs can be tricky because the drawdown (the time it takes for coffee to drain from the filter into the carafe) is a crucial part of their design.

It is easier to shorten the brew time than to prolong it if you’re using a Chemex or Hario V60– There is no more water available for extraction once the coffee has been placed in the carafe.

For small increments of time, such as 15 to 30 seconds, you can increase your brew time on a clever dripper and note the flavor it produces.

cropped view of a barista brewing with the Aeropress in the inverted method to avoid sour coffee

Dilemma: Aeropress Is Brewing Sour Coffee

Resolution 1: Grind it finer

A finer grind size will improve the taste of your Aeropress coffee or your espresso if it tastes sour.

Unlike other extraction methods, these are capable of extracting in a matter of seconds, which means that the grind must be fine enough to enable the extraction to occur rapidly.

Resolution 2: Turn your Aeropress upside down (inverted method).

How can turning a machine upside down fix sour coffee problems?

When you brew with the Aeropress, there will be some under-extracted coffee dribbling into your cup from the brew chamber.

This can lead to a sour taste in your cup of coffee.

The solution has been to flip the Aeropress upside down to brew the coffee without a sour taste.

Once the brew cycle has ended, you place the mug on top of the chamber, flip it over, and then enjoy your hot coffee and grounds (hopefully without flooding your kitchen, office, or campground).

Here’s a detailed article that explains how it all works.

It’s All About Choosing Beans You Love!

The right type of beans can dramatically affect how your coffee tastes and whether or not it is sour.

Try using beans that are roasted a lighter color, such as light to medium roasts. This will brew a less acidic yet sweeter coffee!

If you’re using an expensive espresso machine, make sure you have cleaned it recently, and your program is still set the way you want it!

I have actually set my machine back to its default settings and re-programmed it. My program started acting a little off for some reason, and I saw excellent results doing this.

Arabica beans can be very sour by nature

Coffee beans have different tastes, and Arabica coffee beans can be sour. This is because they are more acidic than other beans.

It may seem overwhelming to taste the fruity flavors of Ethiopian or Kenyan coffee if you’re used to darker roasts. 

Furthermore, the fruity flavors can actually appear sour, when in reality, you aren’t accustomed to fruitiness in coffee.

Coffee lovers who like an earthy, smoky taste will be looking to get their coffee from African coffees such as Ethiopian Harrar or Kenyan Tungurahua.

You may also want to try Sumatran Coffee, which is known for its fruity and floral notes. This type of bean has been used in the production of blends because it adds a hint of sweetness to any brew!

This can be solved easily by placing your grinder to the finer settings.

In addition to providing a better cup, this will increase extraction. 

In my experience, moving the grinder in 1 or 2 increments at a time allows you to determine what works best easily.

Don’t hesitate to write down what settings you like and don’t like. If you’re using an electric grinder, you can save your settings, but if you’re using a manual model, then you will want to remember what settings you like for the brewing process you love to use.

How To Taste Good Acidity:

If you’re looking for a coffee with more acidity, experiment with different beans. Different roasts will have varying degrees of acidity- but the lighter your roast is, the sourer it will be!  

A girl standing in front of a pink background holding her chest after taking a sip of her sour coffee

Why does hipster coffee Taste sour?

Hipster coffee is sour because it’s roasted darker and brewed with higher water temperatures.

Sour, acidic coffee beans are used in the “hipster” coffee roasting process.

Corner cafes use a light roast to get a quality strong flavor. 

The same light roast beans are used for hipster coffee. In addition, a sour taste is also associated with hipster coffee, helping fuel this trend.

Why Does My Cold Coffee/Cold Brew Taste Sour?

Coffee that has cooled down will taste sour because the temperature plays a huge role in the flavor of your coffee.

If your cold brew(ice coffee) tastes too bitter, it’s likely because the coffee was brewed for too long or ground too finely.

If your cold brew tastes sour, it’s likely to be under-extracted. To balance out the flavor, change one of the following: brewing process time, grind size, or beans used.

How can you tell the difference between sour and bitter coffee?

Different brewing methods may result in a sour taste or bitter flavor variations, and sometimes it is hard to tell the difference.

The former causes a sharp, stinging sensation, whereas the latter leaves an aftertaste.

The answer to how coffee should taste is not clear – some prefer a sweeter cup, whereas others prefer something bitter.

The concept is not to evaluate whether one coffee bean has a better or worse taste than another. A sour cup of coffee doesn’t mean a quality bean was used or a subpar product.

Should Espresso Be A Little Sour

No. Espresso should not be sour because it traditionally has a robust flavor; it should have a rich caramel mouthfeel.

If it tastes too acidic, like lemon or grapefruit, there’s a problem with how you’re brewing coffee or the type of beans your choosing.

Under-extracted coffee tastes sour, and I guarantee this is what happened if you’re experiencing this.

The coffee oils in the coffee grinds are subjected to high pressure in espresso machines, and while they’re under extraction, all of the flavors are pushed out, giving you a vibrant, caramel-like flavor.

It is unlike any other coffee taste or brewing method, and this is why you have to be very careful not to cause under extraction.

How To Know Your Coffee Is Sour

Coffee tastes sour when it’s very acidic, like lemon or grapefruit.

If the coffee beans are too light, they will taste grassy and brew sour coffee. If they’re old and stale, the flavor will be a lot more sour than usual, especially if you’re making hot coffee.

But, the chances are that the problem is not the beans– it’s how you’re brewing coffee.

So to avoid making your coffee sour coffee next time, make an adjustment or two with your brewing method to prevent under-extracted sour coffee.

If you’re not sure about how your cup of coffee should taste, then go to your closest cafe and ask them if they roast their own beans.

Or look into a coffee tasting where you will know if they’re using fresh coffee, a lighter or darker roast, the specific brewing time, and you can ask them the extraction time.

This will allow you to experience the true flavor components of coffee in a way that you know it is being prepared correctly. This way, if you observe sour flavors in a french press prepared beverage, you know this is the right amount for the next time you use your french press or buy from your local cafe.

If they do order a black coffee and this will be the flavor you’re looking for.

Don’t Confuse Acidity with Sourness

We need to keep in mind that coffee includes natural acidity. So it’s good to have acidity in your coffee! However, many people mistakenly think it’s why your coffee tastes sour.

Its pleasant acidity distinguishes bright, crisp, and vibrant-tasting coffee.

Imagine acidity as soda’s carbonation. The soda would taste flat and boring without the tangy pop of carbonation. A coffee without acidity isn’t as exciting as it should be.

Acids found in coffee are divided into four major types:

  • Acids Citrus – Lemons, limes, oranges, notes of citrus
  • The taste of malic acids is reminiscent of green apples
  • Notes of sweetness and tanginess in phosphoric acids
  • Acidic acids – Taste like sour beer or vinegar.

Each global coffee cup is unique in terms of the amount of acid, which contributes to its flavor. 

Coffee beans from Brazil, for example, are usually smooth, nutty, and sweet-tasting due to their lower acidity. 

East African coffee beans, such as those from Zambia and Ethiopia, are known for their fruity, zingy flavors.

Life is full of plenty of good things, but too much can be detrimental. For example, if it is too acidic, it will make your coffee sour and harsh. Overroasted coffee or improperly brewed coffee leads to this problem. 

To emphasize and compliment the natural flavor of the coffee beans, specialty coffee professionals roast and brew coffee with acidity.


We hope this article has helped you understand why your coffee may be tasting less than stellar.

If you have any questions or comments about anything, we’ve said here today, feel free to leave them below!

Thanks for reading, and happy brewing!