Why Does Your Espresso Taste Sour? (And How to Fix It)

Do you ever find yourself eagerly waiting to take the first sip of your morning espresso, and find it sour?

If so, you’re not alone. There are lots of people who brew unpleasant espresso shots in the beginning.

However, if you know the exact reasons behind it, you can start working on your skills and learn to brew a good one.

In this article, I will tell you the reasons why the espresso you have brewed tastes sour. Also, I will tell you how you can fix the taste and start brewing a perfect one onwards.

Let’s start.

Common causes of sour espresso

1) Under-Extraction

Sourness in espresso often results from under-extraction. This occurs when the water flows through the coffee grounds too quickly, failing to extract the full spectrum of flavor compounds.

The acidic and bright notes overpower the shot, leading to a sour taste.

2) Inadequate Coffee Dose

Insufficient coffee grounds in the portafilter can lead to under-extraction and sourness.

When there isn’t enough coffee to interact with the water, the shot lacks the necessary depth and flavor concentration, resulting in a sour and weak espresso.

3) Improper Tamping

Tamping is an essential step in the espresso-making process. Inconsistent or insufficient tamping pressure can lead to uneven distribution of coffee grounds in the portafilter.

This irregularity can result in uneven extraction, where some parts of the puck under-extract, causing sourness.

4) Water Temperature

Water temperature significantly affects the extraction process. If the water is too cool, it will not extract the coffee’s full flavor potential.

Under-extraction can occur, leading to a sour espresso, as the water fails to dissolve the desirable compounds effectively.

5) Water Quality

The quality of the water used for brewing espresso is crucial. Water with impurities or high mineral content can interfere with the extraction process, affecting flavor.

Poor water quality may contribute to sourness as it does not interact optimally with the coffee.

6) Coffee Bean Selection

The choice of coffee beans plays a pivotal role in the flavor profile of your espresso.

Some coffee beans inherently possess brighter and more acidic characteristics. Selecting beans with profiles that are not well-suited for espresso can result in a sour taste, as these flavors dominate the shot.

7) Grind Size

Grind size directly influences the rate of extraction. If the grind size is too coarse, water flows too quickly through the grounds, causing under-extraction and sourness.

A finer grind is required to slow down the flow and achieve a balanced extraction.

8) Inconsistent Grinder

An inconsistent grinder produces varying particle sizes in the coffee grounds.

This inconsistency can lead to an uneven extraction, with some grounds under-extracting and others over-extracting. The under-extracted portions contribute to the sourness of the espresso.

How to fix sour espresso?

1) Adjust the Grind Size

A finer grind size slows down the extraction process which allows for more contact time between the water and coffee grounds. This adjustment can help correct under-extraction, reducing the sourness in your espresso.

Gradually you need to make your grind size finer and pull another shot. Continue adjusting until you find the right balance.

2) Modify the Coffee Dose

Increasing the amount of coffee in the portafilter can enhance flavor concentration and correct under-extraction. A higher coffee dose can help mitigate the sourness by providing more grounds for the water to interact with.

Adjust the coffee dose by adding more coffee grounds to the portafilter. Be sure to maintain an even distribution of grounds.

3) Reevaluate Tamping Pressure

Ensuring even and consistent tamping pressure is crucial for uniform extraction. If your tamping technique is inconsistent, it can lead to channeling and under-extraction.

You need to practice consistent tamping pressure and technique. Use a tamper that fits the portafilter basket perfectly to achieve an even surface.

4) Check Water Temperature

Water that is too cool can contribute to under-extraction. Make sure your espresso machine’s temperature is in the optimal range (usually around 195°F to 205°F or 90°C to 96°C).

Adjust your machine’s temperature settings as needed to ensure the water is at the correct temperature for extraction.

5) Use High-Quality Water

Poor water quality with impurities or excessive mineral content can negatively affect the flavor of your espresso. Using filtered or bottled water can help ensure consistent and suitable water quality.

It is better to switch to filtered or bottled water for brewing your espresso.

6) Choose the Right Coffee Beans

Opt for coffee beans that are well-suited for espresso and have a flavor profile that complements your taste preferences. Beans with balanced acidity and sweetness can help counteract sourness.

Experiment with different coffee beans and select those that have profiles better suited for espresso brewing.

7) Ensure Consistency in Grind Size

An inconsistent grinder can produce grounds with varying particle sizes, leading to an uneven extraction. This can contribute to sourness in some parts of the shot.

Invest in a high-quality burr grinder that consistently produces uniform coffee grounds.

8) Practice A Lot

Achieving a balanced shot of espresso requires precision and patience. Be methodical in your adjustments, and don’t rush the process. Small changes in grind size, coffee dose, or extraction time can have a significant impact on flavor.

It is better if you keep a log of your adjustments and the resulting flavor changes to fine-tune your brewing technique over time.

Wrapping up

Here, I have got you covered with the causes of espresso sourness.

When faced with sourness in your espresso, remember that it’s a common challenge encountered by both beginners and seasoned baristas.

By recognizing the causes of sourness, whether it be under-extraction, improper grinding, or inconsistent brewing, and by implementing the appropriate adjustments, you can transform your espresso-making skills.