Why does my coffee taste sour?

Written by: Smilla H.



Time to read 11 min

Has your love for coffee manifested itself in your brand new Moccamaster or in your morning hand brewing routine with the V60 hand filter ?

Of course you also thought about the right coffee . Three different varieties from the best roasters you know. You tear open the first package and smell the freshly roasted coffee beans expectantly. From chocolaty, nutty flavors to fruity and floral notes, you can't wait to taste them all. The beans immediately fly into your hand grinder and into the filter coffee machine. You start. Disillusionment. The coffee tastes too sour. Way too sour. I'm not talking about a pleasant acidity like filter coffee. Your taste buds contract.

Even the most experienced coffee lovers can be surprised if the coffee has a too sour note. Before you demonize your new coffee machine and your specialty coffee beans, read this article.

In addition to the right grind, roast and origin, the sour taste of your coffee can have surprising other reasons.

Why does my coffee taste sour? 5 possible reasons.

The sour taste in coffee can have many different and sometimes surprising reasons. Sour nuances in coffee don't always mean something bad. In fact, acidity in coffee can be a desirable characteristic that enlivens the flavor and gives it exceptional freshness. Lightly roasted coffee beans with a higher acid content are particularly popular in the specialty coffee scene. So sour is not the same as sour.

So let's explore the main reasons why your coffee tastes sour.

1st reason: type of coffee beans

The type of coffee beans you use can make your coffee taste sour. The fact whether it is an Arabica or Robusta bean has a significant influence on the taste of the coffee. Some types of coffee beans from certain coffee regions tend to have higher acidity than others. The Arabica bean tends to be more acidic than the Robusta bean. Robusta beans give coffee its bitterness, depending on how it is roasted. This is due to the different chemical profiles of the beans. However, that doesn't mean that your coffee with a high Arabica content will taste sour.

In addition, sometimes bad beans sneak into your coffee. This can happen to you from time to time, even with expensive coffees. Just brew yourself another cup. If it was actually a bean, your next coffee will no longer taste sour!

2nd reason: degree of roasting

The degree of roasting of the coffee beans also plays a crucial role. The lighter the roast, the more acid is retained in the coffee. Darker roasts, on the other hand, develop lower acidity and often have a stronger, earthier taste. One of these valuable acids in the coffee bean is chlorogenic acid. More on that later.

Reason 3: Brewing method and time

The way you prepare your coffee can affect the acidity in your coffee. A brew time that is too short or a grind that is too coarse can result in too much acid being extracted. If your grind is too coarse, your coffee will usually run through the filter too quickly.

4th reason: ratio of coffee and water

This is where the good old coffee scale shines, because there are also sources of error in the ratio of coffee to water. Simply put, if you let too little water run through too many grams of coffee, your coffee will taste sour and simply not particularly balanced.

A good starting point is a ratio of 1:2. That means, for example, 19 grams of coffee powder, 38 grams of coffee in the cup.

If your coffee tastes too sour, run a little more water through your coffee. Light roasts in particular benefit from a little more water. You can play here with ratios up to 1:3 without any worries.

5th reason: water temperature & water quality

Another relevant topic is the correct water temperature. Ultimately, it provides the energy for chemical reactions in your brew. In our case for breaking down chemical compounds.

The brewing temperature of your coffee should be between approximately 90° and 94°. If you're too impatient, you'll brew too coldly. The result: Your coffee tastes sour. Lighter roasted coffees in particular are often unforgiving of low temperatures. So it's worth waiting an extra 10 minutes for your cup of coffee.

The quality of the water you use for brewing can also play a role. If you can rule out all other factors, take a closer look at the water you brew with. At the end of the day, your espresso will consist of at least half of it! For example, if your water is too soft, your espresso may taste a little too sour. You can remedy this with Third Wave Water, for example. With the addition you create the perfect conditions so that your coffee no longer tastes sour. Sound crazy? I would be happy to tell you more about how the taste of your coffee changes with water in another article .

Now that we know the main reasons for sour coffee, let’s delve a little deeper into the topic.

Why does my coffee taste sour? - the role of coffee beans.

Origin and cultivation of coffee beans

The origin of the coffee beans has a significant influence on their taste. Coffee is grown in different regions of the world and at different altitudes, and each growing area has its unique climatic conditions and soils. What does origin have to do with why your coffee tastes sour?
These soil and elevation factors influence the flavor profile of the coffee beans. For example, coffees from Ethiopia tend to be fruitier and more acidic, while coffees from Brazil often have less acidity but a nuttier taste.

Types of coffee and their acid profiles

There are two main types of coffee beans that are most common in the coffee world: Arabica and Robusta. Arabica beans generally have higher acidity than Robusta beans. This is one of the reasons why Arabica is considered to be of higher quality. If you like sour coffee, you should look for Arabica varieties. Unfortunately, it's not quite that simple. Every single type of coffee and coffee variation brings with it a range of flavor nuances. This complexity in terms of taste makes such categorization difficult.

Coffee origin countries and their acid profiles

When it comes to the taste of coffee, it is worth taking a closer look at the countries of origin of the coffee. It is also impossible to say generally which coffee tastes sour, but there are clear tendencies.

Ethiopia : Coffee from Ethiopia, the country of origin of Arabica coffee, is considered one of the best and most traditional in the world. It is grown in the high regions of the country and is characterized by light and floral notes.

Burundi : Coffee from Burundi, an emerging coffee-growing country in East Africa, impresses with its remarkable variety of flavors. With a pleasant balance between fruity nuances of berries and a slightly spicy depth, Burundian coffee is an exciting discovery for discerning connoisseurs.

Influence of the degree of roasting on the acidity in coffee

The degree of roasting of the coffee beans is a decisive factor in the taste of the coffee. A lighter roast retains more acids, while a darker roast reduces the acidity. This means that light roast coffees tend to taste more acidic, while dark roast coffees have a bolder, less acidic taste.

Why does my coffee taste sour? - Coffee preparation and acidity.

Coffee machines and methods

The way you prepare your coffee can significantly affect the acidity. There are many different coffee machines and methods to choose from - each with its own influence on the taste. For example, espresso machines often produce a more concentrated coffee with less acidity (of course this varies depending on the type of coffee), while filter coffee machines tend to produce a lighter, more acidic coffee.

Influence of brewing time and temperature on acidity

The brewing time and the water temperature are crucial for the acidity in the coffee. The coffee tastes sour if the brewing time is too short. A brew time that is too short or a grind that is too coarse can result in too much acid being extracted. If your grind is too coarse, your coffee will usually run through the filter too quickly. This is because with coarse grinds there is more air between the particles. Imagine it this way. There are pebbles in one tube and sand in the other. If you pour water on it, which pipe will it flow through faster? The situation is similar with ground coffee. Fine powder increases resistance, brewing pressure and your brewing time.

Coffee extraction and acidity

Extraction is another important factor. If your coffee is under-extracted, not enough flavors have been extracted from the beans, which can lead to a sour taste. Conversely, over-extraction can result in a bitter taste. Finding the right balance is crucial to making coffee with the desired level of acidity. Does your coffee taste sour? Try reducing the amount of coffee powder a little. Here you can find out how you can influence the taste of your V60 hand filter during coffee extraction. In another article I will go into more detail about the dosage of coffee and the taste.

Coffee tastes sour - taste and acid in coffee.

Sensory properties of coffee

The sensory system of coffee includes the ability to recognize the different aromas and flavors in coffee. The acid is just one of many components. Coffee can also have notes of fruits, flowers, chocolate, nuts, and other flavors. Finally, acidity gives coffee a certain brightness and freshness that can improve its overall flavor.

Does your coffee taste deliciously sour? Acid as a quality feature!

In the world of coffee, acidity is often viewed as a sign of quality. Coffees with balanced acidity are often considered to be of higher quality because they offer a more vibrant flavor palette. This acidity gives the coffee a certain elegance and depth that is appreciated by coffee lovers.

Sour is not the same as sour - different acid flavors in coffee

Not all sour coffees taste the same. There are different types of acid in coffee including citrus, apple, berry, and more. Each type of acid gives the coffee a unique flavor. For example, the acidity in an Ethiopian coffee may be reminiscent of lemons, while the acidity in a Colombian coffee may be more reminiscent of apples.

Chlorogenic acid is an ester of caffeic acid and is also present in other plant foods such as nettles, valerian and St. John's wort. The term “acid” can be confusing in this case. Chlorogenic acid is one of the antioxidants and therefore has positive properties on the human organism. If you would like to find out more about coffee and the health effects on our bodies, I of course have reading material for you on this topic too!

What to do if the coffee tastes sour? Tips and tricks about the coffee bean and machine.

Choosing the right coffee beans - Discover freshly roasted coffee from Europe's best roasters

Your taste buds are not very sensitive to acid and you prefer drinking coffee with a sour taste profile? Then you should look for Arabica varieties, especially from the popular regions of Ethiopia, Kenya or Colombia. Also pay attention to the roast level, as lighter roasts tend to have more acidity!

At 60beans, we work with the best coffee roasters to find you exactly the coffee you are looking for and deserve. With our taste finder you can simply try it out until you find exactly the right one!

Adjusting your brewing method

Does your coffee taste sour? This is not necessarily due to the coffee beans you choose. Also experiment with your brewing method to achieve the desired level of acidity. Change the brewing time, water temperature and grind until you achieve the perfect acidity level in your coffee.

The importance of water quality

Use high-quality water to make your coffee. If your tap water is too hard or rich in minerals, this can affect the taste. Consider using filtered or specially treated water. You can find out more about water quality here !

Storing your coffee beans

Coffee should always be made from fresh beans. Make sure to store your coffee beans in an airtight container in a cool, dark place to preserve freshness. You can also find the right accessories online for storing your favorite coffee beans.

Conclusion: Why does my coffee taste sour?

Overall, sour coffee isn't necessarily a problem, but rather a matter of personal taste. If your coffee tastes a little sour, that's not necessarily a negative thing, but perhaps even a sign of quality.

In addition to the type of coffee beans, the degree of roasting, the right brewing method, the quality of the water used and how you store your beans, one thing is most important: find the coffee beans that suit you and that you really enjoy!

Because with the right, freshly roasted coffee beans and your favorite preparation technique, you can adapt your coffee so that it exactly meets your preferences and develops the perfect acidity. Take the time to experiment. Have fun!

FAQ: 5 reasons why your coffee tastes sour

Why does my coffee taste sour?

The sour taste in coffee can be due to a variety of factors, including the type of coffee beans, roast level, brewing method, water quality, and the freshness of your beans.

Is acidic coffee bad for your health?

No, acidic coffee is not necessarily bad for your health. However, the acid in coffee can cause stomach problems for some people. If you are sensitive, you should choose milder coffees or coffees with lower acidity.

Which types of coffee have the highest acidity?

Coffees from Ethiopia, Kenya and Colombia are known for their high acidity. These regions often produce coffees with lively, fruity notes.

Can you temper acidic coffee?

Yes, you can moderate the acidity in coffee by choosing a darker roast, increasing the brewing time, and increasing the water temperature.

Why is acidity in coffee often viewed as a quality feature?

Acidity in coffee is often considered a sign of quality as it adds freshness and depth to the taste, providing a diverse range of flavors appreciated by coffee lovers.

Which coffee beans are best for low acid coffee?

If you prefer low-acid coffee, you should use Robusta beans or dark-roasted Arabica beans.

Can I influence the acidity of my coffee through how I prepare it?

Yes, the way you make your coffee can affect acidity. The brewing time, water temperature and grind are crucial factors.

How do I store coffee beans to maintain freshness?

Coffee beans should be stored in an airtight container in a cool, dark place to preserve their freshness