Why does my instant coffee taste sour? (Why is my instant coffee sour? + More information)

Have you ever craved a quick cup of coffee only to have it and find out it tastes sour? You might have asked, “Why does my instant coffee taste sour?” Read on to find out.

There are several reasons why instant coffee might taste sour. Some common reasons include using low-quality coffee, using more coffee with less water, and using coffee that has gone stale. Instant coffee tasting sour should not be a reason for alarm as it is pretty common. I have also been in a state where my coffee tastes sour. Luckily, I consulted with my mom, who is a self-proclaimed coffee expert, and she gave me the solution. She advised me to change my coffee brand and opt for more quality instant coffee. Because many people face this problem, I decided to write this article to analyze why instant coffee might taste sour and how to fix the issue. Keep reading to learn more.

What makes instant coffee taste sour?

Low-quality coffee

Instant coffee is made from dried and processed coffee beans, and the quality of those beans can affect the taste of the final product. If the beans used to make the instant coffee are of low quality or have been over-processed, they may have a sour taste.


Instant coffee is made by brewing coffee and then removing the water to leave behind a concentrated coffee extract. If the coffee is over-extracted during the brewing process, it can lead to a sour taste. Furthermore, if the water is low compared to the amount of coffee, then you will get a sour cup of coffee.

Poor storage

If instant coffee is not stored correctly, it can absorb moisture and become stale. Stale coffee or coffee that has overstayed in your pantry has a sour taste, which is almost off. You can easily know if your coffee has gone stale, and you should avoid consuming such coffee.

Water temperature

The temperature of the water used to make instant coffee can also affect its taste. If the water is too hot, it can extract more bitter compounds from the coffee. The result will be a sour cup of coffee.

How do you fix instant coffee that tastes sour?

Why does my instant coffee taste sour?
Instant coffee making. Image source: Pixabay

Adjust the water temperature

As mentioned above, if the water you used to make the coffee was too hot, it could have extracted more bitter compounds from the coffee, leading to a sour taste. Try using slightly cooler water to see if this fixes the taste of your coffee.

Use high-quality instant coffee

If you consistently find that your instant coffee tastes sour, it may be worth trying a different brand to see if the taste is more to your liking. If you have shifted to high-quality instant coffee and your coffee still tastes sour, you can try diluting it with hot water to reduce the sour taste.

Store properly

As stated earlier, your coffee can go sour if it has gone stale. To ensure your coffee does not go stale, you have to store it properly. The best way is to store your coffee in an air-tight container and keep it away from moisture.

Add a sweetener

Adding a sweetener like sugar, honey, or maple syrup can help balance out the sourness of the coffee. Besides adding a sweetener, you can add milk or cream to your coffee, as it can help neutralize the acidity in the coffee and create a smoother, creamier taste.

FAQ Section

Is sour-tasting instant coffee bad for you?

Sour-tasting instant coffee may not necessarily be bad for you, but it may indicate that the coffee has gone stale or has not been stored properly. Coffee that has gone stale may have lost some of its flavor and aroma, but it is generally safe to consume. Furthermore, sour instant coffee may just be an indicator you have prepared your coffee with less water or extra hot water. This cannot harm your health in any way.

Does instant coffee taste sour when cold?

Yes, instant coffee might taste sour when cold. This is because when coffee becomes cold, it gradually loses flavor and might gain a sour taste.

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