Why does my coffee taste sour?

As a follow-up to my most-read blog Why does my coffee taste bitter, I would now like to explain the other extreme to you.

Bitter and sour are often diametrically opposed, but bitter is also a type of sour. Sound complex?

If you just know what to do about it, it's not that bad. In this blog post, I'll explain what sour coffee is, what you can do if your coffee tastes too sour, and which coffee beans aren't sour.

Read on to find out why your coffee tastes sour.

What is sour coffee

#acidityisnotacrime

First, I want to start with the assumption that a little sourness, acidity, or fruitiness isn't inherently bad. In other words: acidity is not a crime (quote from Gardelli Specialty Coffees) .

It's true that coffee was traditionally roasted so dark that we've become accustomed to the bitter, dark flavors of burnt coffee. So, it's a bit of a change.

However, this involved lower quality coffee.

Today, we, and many other specialty coffee roasters, work with ' specialty coffee ' or 'thirdwave coffee'.

This is a very good quality coffee that requires much less dark roasting because the bean itself already contains wonderfully beautiful and rich flavours.

After all, it's the pit of a berry, and a berry is somewhat tart, so it makes perfect sense! Admittedly, it took me a while to get used to it too.

But once you've taken that path, you can't and won't want to go back. If you learn to appreciate the milder flavors, you'll be able to taste many more subtle (and not so subtle) nuances in your cup.

In addition, some countries of origin have coffee beans that have more acidity than other countries.

For example, Kenya scores exceptionally high on acidity, while Brazil tends to be more moderate in these flavor notes. Sour coffee therefore has a lot to do with its origin.

Also read: Where does coffee come from?

Causes of sour coffee

Sour coffee can have several causes. Sometimes it's a matter of preference or habit, but often it's due to technical aspects of roasting or brewing the coffee.

Below you'll find an overview of the most common causes of sour coffee and how to recognize them:

Causes:

1. Underdeveloped coffee beans

   • Coffee beans that aren't roasted long enough don't develop all their flavor components. This leads to an unbalanced, often sour flavor.
     
     

2. Under-extraction

   • When coffee is not extracted long enough, for example due to a grind that is too coarse, a short brewing time, or low water temperature, sour flavors continue to dominate.
     
     

3. Country of origin

   • Some coffee beans, such as those from Kenya or Ethiopia, are naturally known for their high acidity. This can be perceived as sour.
     
     

4. Incorrect ratio of water to coffee

   • Too little coffee in relation to the water will prevent the flavors from fully developing, which can lead to a sour and watery coffee.
     
     

5. Too low water temperature

   • If the water is too cold (below 92 degrees), the coffee will not be extracted properly, which can cause a sour taste.

With these insights you can easily analyze where things go wrong and improve your coffee preparation.

Underdeveloped

Coffee beans that haven't been roasted long enough can be underdeveloped. This means there hasn't been enough time for all the flavors in the coffee to develop for a balanced taste.

In practice, this can often happen with light-roast coffees. With medium- or dark-roast coffees, this is almost impossible.

The chance that your coffee tastes too sour probably has to do with the following

Underextraction

A common consequence of poor coffee is coffee extraction problems. If coffee isn't brewed properly, which is very easy to achieve, you often end up with acidic and watery coffee (or rich and bitter ) .

This is usually the result of under-extraction, or over-extraction in the case of bitter coffee. The complexity is that there's no single cause.

This could be due to the grind, but also to the water temperature, the amount of ground coffee or the ratio.

How do you make coffee less acidic?

How to make coffee less acidic

We explain sour coffee as a result of under-extraction using the ultimate espresso recipe .

Of course, you can also create under-extraction with other brewing methods such as the V60 or Chemex , but here we assume an espresso recipe.

Espresso is the basis for almost all coffee types . If you master this, there's a good chance that your cappuccino, flat white, and Americano will also be top-notch!

Assuming you can reproduce the basic recipe of 19:40 grams well (see a blog post with instructions for this basic recipe here ), you can try influencing other factors:

1. If your coffee isn't brewing super slowly yet, say, up to 25 seconds, you could try grinding it a bit finer. This will extend the extraction time to about 30 seconds.
   
   
2. If possible, you can increase the water temperature. A lower water temperature will more quickly lead to under-extraction and therefore sour coffee. Ideally, use water between 92 and 96 degrees Celsius.
   
3. If the above tips don't help and you don't get used to the fruity flavors in the coffee, I would advise you to choose a coffee from a different country of origin to see if that makes a difference for you.
   
   
4. If that doesn't do it for you, perhaps you're more of a fan of darker roasts... Tastes differ, of course!

Ever wanted to know how to make the perfect espresso? Then read: How to make espresso in 6 easy steps.

Which coffee beans are not sour?

So if you really don't like a fruity coffee flavor or an exciting twist in your coffee, you'll probably find many specialty coffees too sour.

But if you want the specialty coffee experience, but you want a fuller and rounder coffee flavor, then I recommend going for a Brazilian coffee or a blend with a large Brazil component.

These coffee beans have more necessary and chocolate notes and contain minimal acidity.

> For a less acidic taste, try our Brazilian coffee beans .

Which coffee roasts are not acidic?

You can also look at the roast level of the coffee. The lighter the roast, the more likely it will contain more acidity.

Then look for a medium+ or a dark roast coffee.

These roasts have less acidity in the end result due to the roasting process.

Which types of coffee beans are less acidic?

You can also look at the types of coffee beans .

Robusta coffee beans are not naturally acidic and tend towards the bitter side.

So you could look for a coffee brand that sells Robusta coffee or a blend that has a large component of Robusta.

Frequently Asked Questions (FAQ) about Sour Coffee

1. Why does my coffee taste sour?

Sour coffee can be caused by underdeveloped coffee beans, under-extraction during brewing, or by the natural acidity of the beans used.

Factors such as water temperature and coffee grind can also play a role.

2. Is sour coffee bad?

No, a certain degree of acidity in coffee is actually considered a quality characteristic, especially in specialty coffee.

It gives the coffee a fresh and fruity flavor. However, if the sour taste is too strong, it could indicate improper preparation or a personal taste preference.

3. What does underdeveloped coffee mean?

Underdeveloped coffee refers to beans that haven't been roasted long enough. As a result, the flavors haven't fully developed, which can result in a sharp or sour taste.

4. How can I prevent under-extraction?

To prevent under-extraction:

• Use a finer grind.
• Extend the extraction time.
• Make sure the water is between 92-96°C.
• Adjust the coffee to water ratio, for example 1:16 (1 gram of coffee to 16 ml of water).

5. Which coffee beans are the least acidic?

Coffee beans from Brazil or blends with a high percentage of Brazilian beans are known for their soft, round taste with less acidity.

Beans from Robusta varieties are also less acidic and have a fuller, bitter taste.

6. How does roasting affect the acidity of coffee?

The lighter the roast (light roast), the more the acidity of the coffee will come to the fore.

Medium roast and dark roast reduce the acidity, making the coffee taste fuller and richer.

7. What is the difference between sour and bitter in coffee?

• Sour: Relates to the natural acidity of the coffee beans and can taste fresh or fruity.
• Bitter: Caused by over-extraction or roasting that is too dark, which can lead to burnt flavors.

8. How do I know if my espresso is too acidic?

If your espresso is extracted in less than 25 seconds or runs too quickly, this could indicate under-extraction. Grinding the coffee finer can solve this problem.

9. Can I sweeten sour coffee?

Yes, you can sweeten sour coffee by improving the extraction balance. Try a finer grind, a higher water temperature, or adjusting the coffee-to-water ratio.

If that doesn't work, choose a less acidic bean, such as one from Brazil.

10. How do I prevent sour coffee with filter methods such as V60 or Chemex?

• Use a slightly finer grind.
• Make sure the water is at least 92°C.
• Increase the brewing time by a few seconds.
• Experiment with a slightly higher coffee/water ratio, for example 1:15.

11. Are fruity flavors the same as sour?

Not necessarily. Fruity flavors in coffee can be an indication of high-quality beans and can encompass a wide spectrum of flavors, such as berries, citrus, and tropical fruits.

This is different from an unpleasant sour taste which is usually the result of a cooking error.

12. What is the best brewing method for less acidic coffee?

Methods such as the espresso machine, the French press, or a traditional filter method with medium to dark roast coffee are suitable for minimizing the acidic notes.

13. How important is water quality?

Water quality is crucial. Water that is too hard or too soft can affect the taste of your coffee. Use filtered water with a neutral pH for best results.

14. Can I get used to sour coffee?

Yes, with time and experimentation, many people can learn to enjoy the fresh, fruity flavors of sour coffee, especially specialty coffee. It helps to start with mildly sour beans and gradually develop your taste.

15. What if I really don't like sour coffee?

If you really don't like sour coffee, go for:

• Darker roasted beans (medium+ or dark roast).
• Coffee beans from Brazil or blends with low acidity.
• Coffee brands that offer Robusta beans or non-acidic blends.

Conclusion: Coffee in balance

Naturally, you'll want the very best cup of coffee. This is a cup of coffee that's perfectly balanced. The sour, sweet, and bitter flavors are extracted from the coffee.

This ensures that your cup of coffee is perfectly balanced. 

If you simply make an espresso poorly, the chances are high that it will taste sour or bitter, or at least be out of balance!

You can make a perfectly balanced cup of coffee from most coffee beans. It just takes a little practice!

Be careful though, you might not be able to stop drinking coffee ;-)