Why does my coffee taste sour?

My coffee tastes 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. Bitter and sour are often diametrically opposed, but bitter is also a type of sour. Sound complex? As long as you know what you can do about it, this is not too bad. In this blog I explain what sour coffee is, what you can do if your coffee tastes too sour and which coffee beans are not sour. Read on and find out why your coffee tastes sour.

What is sour coffee


First of all, I want to start with the assumption that a sourness, acidity or fruitiness is not necessarily bad. In other words; acidity is not a crime (quote from Gardelli Specialty Coffees) . It is true that traditionally coffee was often roasted so dark that we have become very accustomed to the bitter and dark flavors of burnt coffee. So just a switch. However, this concerned lower quality coffee.

Nowadays we, and many other specialty coffee roasters, work with ' specialty coffee ' or 'third wave coffee'. This is very good quality coffee that you don't have to burn as dark because the bean already contains super nice and rich flavors.

After all, it is the kernel of a berry, and a berry is a bit sour, so very logical! Admittedly, it took me some time to get used to. But once you've started down that road, you don't want to and can't go back. If you learn to appreciate the milder flavors you can taste much more subtle (and less subtle) taste nuances in your cup.

In addition, some countries of origin have coffee beans that have more acidity than other countries. For example, Kenya scores super high on the bar of acidity, and Brazil is usually a bit more moderate in these taste notes. Sour coffee has a lot to do with where it comes from.

Read also: Where does coffee come from?

What if coffee is too acidic?

But now we move on to the less desirable sides of 'sour' coffee. The fact that coffee is perceived as sour, apart from the above as a result of a milder roast or the country of origin, may have the following cause.


Coffee beans that have not been roasted long enough may be underdeveloped. This means that there has not been enough time to develop all the flavors from the coffee for a balanced taste. In practice, this can often occur with 'light-roast' coffees. This is almost impossible with medium or dark roast coffees. The chance that your coffee tastes too sour is probably related to the following


If a coffee is not brewed properly, which is very easy to achieve, you often end up with sour and watery coffee (or full and bitter coffee ) . This is usually the result of under-extraction, or over-extraction in the case of bitter coffee. The complicated thing about this is that there is no single cause. It can be the grind, but also the water temperature, the amount of ground coffee or the ratio.

Why is my espresso sour?

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. The espresso is the basis for almost all types of coffee , if you nail it, there is a good chance that your cappuccino, flat white and americano are also top!

Assuming you can reproduce the basic recipe of 19:40 grams, see here a blog with instructions for this basic recipe, you can try to influence other factors:

  1. If your coffee is not yet super slow, for example up to 25 seconds, you could try grinding it even finer. This extends the extraction to about 30 seconds.

  2. If possible, you can increase the water temperature. A lower water temperature causes under-extraction and therefore sour coffee more quickly. Ideally, you use water between 92 and 96 degrees.
  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 with a different country of origin to see if this makes a difference for you.

  4. If that doesn't do enough for you, you might be more of a fan of dark(er) roasts... Tastes differ, of course!

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

    Which coffee beans are not acidic?

    So if you really don't like a fruity or exciting twist in your coffee, you will probably find many specialty coffees too sour. But if you do want the specialty coffee experience, but if you want a somewhat fuller and rounder coffee taste, I recommend going for a Brazilian coffee or a blend with a large Brasil component. These coffee beans have more nutty and chocolate notes and contain minimal acidity.

    Which coffee roasts are not sour?

    You can also look at the roast degree of the coffee. The lighter the coffee beans are roasted, the greater the chance that there will be more acidity in the coffee. Then look at a medium + or a dark roast coffee. Due to the roasting process, these roasts have less acidity in the end result.

    Which types of coffee beans are less acidic?

    You can also look at the types of coffee beans . Robusta coffee beans are naturally not sour and tend to be more bitter. So you could look for a coffee brand that sells Robusta coffee or a blend of which a large component is Robusta.

    Balanced coffee

    Of course you go for the best cup of coffee. This is a cup of coffee that is completely balanced. Here the sour, sweet and bitter flavors are extracted from the coffee. This ensures that your cup of coffee is perfectly balanced.  If you simply brew an espresso badly, the chances that it will taste sour or bitter, or at least be out of balance, are very high! From most coffee beans you can make a perfect cup of coffee that is completely balanced. You just need a little practice! Be careful, soon you won't be able to stop drinking coffee ;-)