Why Does My Coffee Taste Bitter, woman reacting to bitter coffee, a cup of coffee in her hand

Why Does My Coffee Taste Bitter

Coffee is one of the most popular beverages in the world, with over 400 billion cups consumed every year. For many people, a good cup of coffee is an essential part of their morning ritual. However, nothing can ruin a cup of coffee more than an unpleasant bitter or sour taste.

Bitterness and acidity are two of the most common flavor defects in coffee, and they can have multiple causes. This article ‘Why does my coffee taste bitter’ will examine the various factors that can make coffee taste bitter and provide tips on how to prevent or fix bitter-tasting coffee.

Overextraction during the brewing process is one of the main reasons why coffee ends up tasting bitter. Overextraction occurs when too much soluble solid from the coffee grounds ends up in the final brew. This can happen due to grind size being too fine, water being too hot, or brew time being too long.

The quality and freshness of the coffee beans also play a huge role in bitterness. Low-quality beans that are over-roasted or stale will inevitably lead to a bitter brew. On the other hand, high-quality arabica beans that are properly roasted and freshly ground make for a delicious, balanced cup of coffee.

Brewing method has a significant impact as well. Methods like french press or espresso are more likely to produce overextraction and bitterness compared to pour over or cold brew. Factors like water quality, grind size, temperature, and brew ratio must be dialed in properly for each brewing method.

This article will explore all these factors in detail and provide actionable tips on how to brew a deliciously smooth cup of coffee that is free from bitterness and acidity.

Key Takeaways: Why Does My Coffee Taste Bitter

Key Takeaways
Bitterness in coffee is often caused by overextraction during brewing due to factors like grind size, time, and temperature.
Choosing high quality, freshly roasted coffee beans and dialing in proper brewing parameters prevents bitterness.
Methods to fix bitter coffee include adding milk/cream, adjusting grind size coarser, using paper filters, and lowering water temperature.
Dark roasts, espresso, and coffee paired with sweets intentionally have bolder, more bitter notes in some cases.
Controlling brew factors like grind size and water temp is critical to prevent overextraction and bitterness in coffee.

What causes bitterness in coffee?

What causes bitterness in coffee

There are several potential causes behind bitter and sour notes in coffee:

Overextraction during brewing

Overextraction occurs when too many soluble solids from the coffee grounds end up in the final brew. This can happen for a few reasons:

  • Using a grind size that is too fine – Finer grinds have more surface area exposed, allowing faster extraction of solubles. An overly fine grind can lead to overextraction in under 30 seconds.
  • Brew time that is too long – Even if grind size is correct, a brew time over 4 minutes can cause overextraction in drip coffee. Espresso is brewed under pressure in under 30 seconds to prevent overextraction.
  • Water that is too hot – Water over 205°F will extract solubles rapidly. Optimal brewing temperature is 195-205°F.

Low quality beans

  • Robusta beans naturally contain about twice the caffeine of Arabica beans, but taste more bitter and harsh. Using 100% Robusta beans will likely result in a bitter brew.
  • Overroasted beans that are roasted past the second crack lose more of their natural flavors, and tend to taste more bitter, ashy, and burnt. Light and medium roasts highlight a coffee’s inherent flavors.
  • Stale or old beans oxidize and degrade over time, losing positive flavor notes and becoming flat, cardboard-like, and bitter. Only freshly roasted beans within 4 weeks of the roast date should be used.

Improper roasting

  • Underroasting fails to sufficiently develop the natural flavors within the beans. Stopping the roast before first crack will lead to sour, grassy, and vegetal flavors.
  • Overroasting scorches the beans, destroying positive flavor notes and producing a bitter, charred flavor. Beans should be roasted only up to light brown with no oil sheen.

Brewing method

  • Espresso is prone to overextraction given the finely ground coffee and high pressure. Bitterness can be minimized with a proper grind and dose, and stopping extraction at 1-1.5 oz.
  • French press has little filtration, so overextraction can occur easily. Using a coarse grind and shorter steep time helps reduce overextraction.
  • Drip machines can overextract without the right grind size and brew time. The flat bottom filter basket and quick brew reduces risk of overextraction.
Cause Description Solution
Overextraction Extracting too many solubles from the grounds Adjust grind size, time, temperature
Low quality beans Robusta, stale, overroasted beans Use fresh, high quality Arabica
Improper roasting Underroasting or overroasting Follow proper roasting guidelines
Brew method Methods like espresso prone to overextract Use optimal method like pour over

Proper brewing is essential to prevent overly bitter coffee. Factors like bean freshness, roast level, grind size, time, and temperature all contribute to balanced extraction and flavor.

How to prevent bitter coffee

How to prevent bitter coffee, woman thinking, coffee maker and coffee cup on the table

There are several methods to prevent your daily cup of coffee from tasting bitter:

Choose high-quality beans

    • Opt for 100% arabica beans, which are smoother and less bitter than robusta beans. Arabica beans contain about half the caffeine of robusta but have more flavor notes.
    • Single-origin beans from reputable specialty roasters will be fresher and highlight unique flavor profiles compared to pre-ground grocery store blends.

Grind beans properly

    • Use a consistent grind size like medium or medium-fine. Grinding too fine leads to overextraction.
    • Only grind enough beans for one use. Pre-ground coffee goes stale rapidly.
    • Use a burr grinder, not blade grinder, for uniform grind size. Blade grinders produce uneven grounds.

Follow correct brewing time and temperature

    • Under-extraction leads to sourness, over-extraction leads to bitterness.
    • Follow recommended time and temperature for your specific brew method.
    • For pourover, 195-205°F and 2-4 minutes is optimal.

Store coffee properly

    • Store beans in an airtight, opaque container at room temperature.
    • Exposure to air, light, heat, or moisture causes beans to go stale faster.
    • Only grind beans right before brewing. Ground coffee stales in minutes.

Clean equipment regularly

    • Change paper filters, backflush espresso machines, etc.
    • Rancid coffee oils will taint flavor. Descale machines to prevent mineral buildup.

Water quality also affects extraction and flavor. Soft, mineral-free water allows even extraction. Hard water or tap water with chlorine may produce an overextracted, bitter brew. Using filtered or bottled water can help.

Method Grind Size Time Temperature
Drip Medium 4-6 minutes 195°F-205°F
Pour over Medium-fine 2-4 minutes 195°F-205°F
French press Coarse 3-4 minutes 195°F-205°F
Espresso Fine 25-30 seconds 190°F-195°F

Dialing in the right grind size, brew time, temperature, and water for your preferred brew method will help prevent a bitter, overextracted cup of coffee. High quality, fresh beans are also essential for balanced flavor.

How to fix bitter coffee

There are several methods to improve or mask the bitter and sour notes in your daily cup of coffee:

Add milk, cream or sweetener

Milk and cream can smooth out and mellow bitterness due to their fat and sugar content. Whole milk works better than low-fat milk.

White sugar, brown sugar, honey and other sweeteners can mask bitterness by overpowering it with sweetness.

Brew a fresh batch

Don’t drink old, stale coffee – the compounds that cause bitterness increase over time after brewing. Always make and drink a fresh pot.

Try cold brewing

The lower temperature used in cold brewing reduces acidity and bitterness by decreasing extraction of these compounds. Can brew coarsely ground beans for 12-24 hours.

Use a paper filter

Paper filters remove more oils and sediment than reusable metal filters. These compounds contribute to bitterness.

Adjust grind size

Grinding coarser prevents overextraction of bitter compounds by decreasing surface area exposed to water.

Grinding finer increases extraction which reduces sourness but risks bitterness.

Lower water temperature

Water at 195°F or lower reduces extraction of bitter oils and acids. 185°F is ideal.

Try different brew methods

Pour over, drip and cold brew are less likely to overextract compared to french press and espresso.

Use fresh, filtered water

Hard tap water or old bottled water can impart minerally, bitter flavors.

Method Grind Brew Time Temperature
Brew fresh coffee Medium 4 minutes 195°F-205°F
Cold brew Coarse 12-24 hours Room temperature
Paper filter Medium 4 minutes 195°F
Adjust grind Coarser Same Same
Lower temperature Same Same 185°F-195°F

Adjusting brewing factors like grind size, water quality, and temperature can help reduce or mask bitterness. Choosing optimal brewing methods and fresh, high quality beans also prevents bitter coffee.

When is coffee bitterness desirable?

While bitterness is often considered an undesirable flavor defect, there are certain styles of coffee and brewing methods where some bitterness is expected and even desired.

  • Dark roasts tend to develop more bitter notes as the roasting process breaks down acids and carbohydrates. Dark roasts accentuate bitterness and decrease acidity and fruitiness. Many coffee drinkers specifically prefer the bold, intense flavor of dark roasts.
  • Espresso is brewed under pressure with very finely ground coffee, leading to high extraction and natural bitterness. A good espresso will have a balance between bitterness and sweetness. The ideal espresso has a thick crema and rich, complex flavor with some bitterness.
  • Coffee paired with chocolate, caramel, or sweet baked goods can benefit from a slight bitterness to balance the sweetness. The contrast makes both the coffee and sweet flavors stand out more.
  • Some coffee drinkers specifically prefer more intense, bitter coffee like dark roasts or ristretto shots. For these drinkers, some bitterness provides a bold, intense coffee flavor.

However, harsh, tongue-coating bitterness is still considered a defect. The degree of desirable bitterness depends on personal taste preferences and the particular coffee style. Balancing bitter notes with other flavors is key.


In summary, bitterness is a common issue that can ruin the taste of a good cup of coffee. Overextraction during brewing due to factors like grind sizetime, and temperature is the primary cause of bitterness. Using high qualityfreshly roasted beans as well as dialing in the optimal brewing parameters for your chosen method are key to preventing a bitter brew.

If you end up with a bitter cup, there are several fixes such as adding milk or sweetener, switching to paper filters, adjusting the grind size coarser, or simply lowering the water temperature. The proper brewing method for the beans and your tastes is also important. While bitterness is generally undesirable, some dark roastsespresso drinks, and coffee paired with sweets intentionally have bolder, more bitter notes.

Overall, controlling the various factors that lead to overextraction during the brewing process is critical to ensure your daily cup of coffee is free of unpleasant bitter and sour flavors. Paying attention to parameters like grind size, brew time, water temperature, and brew method will help yield a smooth, balanced, flavorful cup of coffee.


Q1. What are the main causes of bitter coffee?

Overextraction during brewing due to factors like grind size, time, and temperature is the primary cause of bitter coffee. Using low quality or stale coffee beans can also cause bitterness.

Q2. How can I prevent bitter flavors when brewing coffee?

Choose high quality, freshly roasted beans. Grind beans to the proper size for your brew method. Follow the recommended time and water temperature for your brewer. Store beans properly to prevent staleness.

Q3. My coffee tastes very sour. How can I fix this?

Sourness in coffee is often due to underextraction. Try grinding the beans finer, increasing water temperature slightly, or extending brew time to extract more solubles. This can help balance acidity.

Q4. I added cream and sugar but my coffee still tastes bitter. What should I do?

The bitterness is likely due to overextraction during brewing. Try brewing a fresh batch with a coarser grind size and lower temperature like 195°F to prevent extracting bitter compounds.

Q5. Is dark roast coffee supposed to taste more bitter?

Yes, the longer roasting process of dark roasts causes the beans to become more bitter but also less acidic. Many coffee drinkers enjoy and expect bolder, more bitter flavor from dark roasts.

Q6. Why does espresso often taste bitter?

The fine grind and high pressure used to extract espresso can cause overextraction and bitterness. Well-made espresso balances bitter notes with sweetness. Bitterness in espresso may indicate it is overextracted.

Q7. What is the best way to brew non-bitter coffee?

Methods like pour over and cold brew are less likely to overextract and produce bitter coffee. Following the proper parameters like grind size and water temperature also prevents bitterness.

Jessica Saint-Pierre
Copywriter at CoffeeLifious | Website | + posts

Jessica is a coffee aficionado who has spent years exploring the world of coffee. She has a deep passion for the art of brewing and enjoys experimenting with different brewing methods to create the perfect cup of cold brew coffee. Her love for coffee has led her to become an expert in the field, and she is known for her meticulous attention to detail when it comes to selecting and brewing the perfect cup. Jessica is also an avid writer who loves sharing her knowledge and experiences with others through her writing.

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