Why Does My Coffee Taste Bitter

Oops! My coffee tastes bitter…

Some days we brew our favorite coffee but alas it tastes horribly bad. It happens so it’s okay. Today, we are going to show you how to brew the perfect coffee. The days of bad tasting coffee is over.

My Coffee Tastes Bitter
Photo Credits: kendra k, Flickr.com

Studies have shown that a large percentage of Americans have at least a cup of coffee daily. In fact, most people cannot function properly without drinking coffee.

Coffee comes in different distinct flavors like chocolate, fruity, nutty or citrus-like flavors. This depends on the variety and the roasting method. They have been proven to contain caffeine (a stimulant), essential oils, vitamins, and antioxidants. 

However, coffee also has its unique taste and it can show different types of acidity and bitterness. It is safe to say that coffee by nature is bitter.

Brewing coffee is partly an art as well as a science. When brewed wrongly, it can evoke diverse shades of acidity from mild to pleasant, harsh, or metallic. 

Most people make common mistakes when brewing coffee with coffee beans, equipment, water, and so on. Knowing your mistakes can help you to correct them and you can start brewing great tasting coffee like a good barista.

If you prefer learning by video, this article is also explained here.

Common Coffee Mistakes

There are many common reasons why your brewed coffee tastes bitter or not exactly as you’d want it to taste. They are summed up under these three main headings below:

  1. The coffee beans.
  2. The quality of water used for brewing.
  3. The coffee maker.

We are going to differentiate between these common coffee mistakes and share tips on how to fix the problem. After reading this article, we are sure you will be able to correctly diagnose the problem with your coffee making. Keep scrolling…

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The Coffee Beans

The importance of using quality coffee beans to a good cup of coffee cannot be overemphasized. Perhaps, you already know that grinding your own coffee beans before brewing is a good practice. 

But occasionally, the quality of your coffee beans might be one of the other reasons your cup of coffee tastes bitter. Here are some problems associated with your coffee beans:

Coffee Bean Species and Their Source

There are two major species of coffee. They are the Coffea Arabica and Coffea Robusta. Coffea Arabica produces coffee beans that have more flavor and they are less bitter compared to Robusta. However, the Arabica plants usually require more care, this makes them more expensive.

Coffea Robusta has more quantity of caffeine and is far more bitter than Coffea Arabica. In addition, Coffea Robusta plants grow faster than the Arabica specie. It is also resistant to pests and cheaper. They are considered low quality as they lack some flavors.

On the other hand, you must learn the distinct properties of coffee beans grown in various parts of the world. For example, the Brazilian, Kona region, Jamaican, Ethiopian or Costa Rican coffee beans are highly recommended.

The Remedy

You must always buy good coffee beans. If you are looking for a less bitter coffee, the Arabica beans are a better choice. They are not difficult to find as most coffee bean sellers deal on the Arabica specie. They are clearly specified on their coffee websites or on the coffee label.

Another great remedy for your bitter coffee is getting coffee beans rather than ground coffee with faint product labels. You may be unable to know the best coffee if you keep buying coffee in this state.

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Stale Coffee Beans

The shelf life of coffee beans is not limitless, regardless of how good they may look or how mildly smell. The moment the beans leave the coffee roaster, they start to lose their flavor. 

The process of roasting produces a lot of CO2 (carbon dioxide) in the beans. Then they leak CO2 via a process called degassing. The longer the coffee beans degas, the more flavor they lose.

If your coffee was not stored properly or they have been on a grocery shelf for a long time, let’s say a year. They may give you a bad tasting coffee after brewing.

It is important to note here that for every twenty-four hour your coffee beans are exposed to air at room temperature, its shelf life will diminish by about 10%. That’s a whole lot of flavor lost.

Even when you properly store the beans, its taste will be affected as a result of the continual oxidation of the coffee essential oils and gases released. This leaves your coffee tasting stale.

The Remedy

It is advisable you discard all stale coffee beans even though it is not a pleasant decision. It is something you have to do. You must always make sure your beans are properly stored. Also, do not keep them for too long. 

Coffee tastes better when it is fresh, which is between 4 days and 2 weeks old. So, it is good you buy the quantity you will need for about one week or at most two weeks. 

You must ensure you grind only the quantity you need per time prior to brewing. Always check the date it was roasted on the coffee label rather than checking for the expiration date.


Freshly roasted beans are still undergoing a degassing process and so haven’t had sufficient time to develop most of the beneficial flavors and essential oils.

So, while it is not a good idea to use stale beans, it is also not advisable to use freshly roasted beans that are not up to 4 days post roasting.

The Quality of Roast and Roasting Method

The quality of the roast affects the taste of your coffee. There are two forms of roast: light roast and dark roast. Dark roast usually tastes much more bitter than the lighter roasts. It is advisable you get a light or medium-light roast instead of medium-dark or dark roasts.

The roasting process requires consistent application of heat all through the roast duration. The method of roasting coffee beans also affects the taste of the coffee. The stronger the coffee beans are roasted, the harsher it gets. 

If you are roasting your beans yourself, maybe you are not doing it correctly. An environment that resembles expert roaster’s equipment must be created for a perfect coffee roast. Sometimes, coffee roasters are not consistent in their roasting. So, you may have bought a badly roasted bean.

The Remedy

If your roast is bad, then find new recipes or coffee maker. You can also try other coffee types or get another batch of your preferred coffee beans.

It is important to note here that the choice of roast all depends on your taste preference. So, if you are not getting the desired taste from a particular roast, try different types until you get one that suits you.

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The Size or Texture of Your Grind

The nature of your coffee grinds plays a big role in your coffee flavor. During brewing, it is essential that coffee grounds are soluble enough to extract great flavors but insoluble enough not to get overly dissolved in the filter system.

There are several compounds that give rise to the flavors of coffee. Some of these compounds are extracted faster from the exterior of the coffee grinds. Others have to be extracted from within the grinds, this takes a longer time.

You can change the extraction of these flavor compounds by simply changing the grind size. A finely ground coffee slows down the movement of water through the coffee grinds. This leads to too much extraction of the flavors which causes the bitter flavors present in your coffee.

In other words, using finely ground coffee extracts more flavors during a brewing process but can make your coffee more concentrated and taste bitter. While a coarsely ground coffee makes a lighter or weaker coffee that tastes sweeter.

The type of coffee you are brewing determines the size of the coffee grounds you will use. For example, a French press coffee requires you to use a coarse grind size while your regular coffee requires a medium grind size.

The Remedy

You should know the different grind sizes required for each brewing method. Also, grinding your coffee beans yourself is important. A good grinder for your home will do

The Quality of Water Used for Brewing

Water used for brewing is another factor that can make your coffee taste bitter. Here are problems associated with the water used during the brewing process:

Using Unfiltered Tap Water

Tap water can contain traces of chlorine or other impurities. Using unfiltered tap water to brew your coffee might not do your coffee taste good. It can change the flavor and taste of your coffee.

The Remedy

Always make sure you filter the water you want to use to brew your coffee. Always make sure your water filter runs cold to ensure proper use.

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Water Temperature

You need a perfect temperature for a good brew. The ideal temperature of water used for brewing coffee is 205-degree Fahrenheit or 96 degrees Celsius. 

Using hot water to brew coffee could destroy some fine flavors and essential oils in the coffee beans. When water is too cool, your coffee might be under-extracted. This will give you a weak coffee.

The Remedy

Use a thermometer to measure your water before you start the brewing process. Alternatively, you can boil your water and allow it to cool for about thirty seconds before you start brewing.

Water Ratio

The ratio of water used for making your coffee also determines the taste of your coffee. Measuring more quantity of coffee into the water can make it taste bitter.

The ratio of water depends on the type of coffee maker you use. But your preference is what counts. If you need a concentrated coffee, add more coffee to the water and vice versa.

The Remedy

You should know the quantity of coffee used for each cup of joe. This is easier when you weigh and measure your coffee and water respectively. Some studies recommend using 55g of coffee for 1 liter of water.

Also, make notes when you get your desired ratio so that you can use that for your future brew.  It is not enough to make 1 perfect cup; you should be able to make it again in the future.

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The Coffee Maker

If your water and coffee beans are just right, then maybe your coffee maker is the reason your coffee tastes bitter. Here are some factors:

Dirty Coffee Maker

Coffee grounds can get accumulated within the filter area or carafe. You must clean your coffee maker immediately after brewing. An occasional deep-clean is also important. Cleaning only the carafe is just not enough. Other parts of your coffee maker like the filter area, water reservoir and so on are important too.

The Remedy

Keep your coffee maker clean. Always clean the entire equipment after each use. It is easier to clean immediately after use before the coffee gets dried on the surface of the equipment.

Once every week or monthly, give it a deep clean using vinegar and baking soda. This will get rid of residual smell or dirt.

Using an Old Coffee Maker

Most people continually use their coffee maker for so many years without realizing that just like everything, it is subject to age. Over time, after constant use, your coffee maker gets old and worn out. 

The Remedy

You need to get a new coffee maker because that is the only thing you can do at this point.

Using the Wrong Coffee Equipment

Most times, people look for alternative ways to make a particular coffee. For example, making an espresso coffee without the machine can give you good results, but it might not give you the precision and consistency an espresso machine will produce.

You may be cutting costs, but then maybe what you just need is that expensive coffee making machine. Additionally, you must pour your coffee into the right serving cup. Ceramic and glass mugs are perfect at home while the stainless steel mug is good for travels.

The Remedy

Use the right coffee maker for any type of coffee you’d want to brew.

Other Reasons Why Your Coffee Taste Bitter

If you have good coffee beans, the right equipment, and the right water, then there are other possible reasons why your coffee tastes bitter. Here are a few:

Over-Steeping the Coffee

The process of steeping refers to a coffee brewing method whereby you mix the coffee grinds directly with water. This is different from when you pass water through a filter. Examples of brewing methods that require steeping are the AeroPress or French Press. You must know the point when you need to plunge.

You must know the exact time it takes to steep your coffee otherwise your coffee over-steeps giving you a bitter flavor. This is caused by over-extraction. It is important you get the extraction right so that you can have a sweet and well-flavored coffee drink.

The Remedy

Gradually adjusts the brewing timing until you get your preferred taste. 


The steeping process is just peculiar to only a few methods like the one mentioned above. When you use the regular drip coffee maker or espresso machine, there are minimal chances of over-steeping your coffee.

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Quantity of Coffee

Brewing coffee more than you need per time is not a good idea. A great tasting coffee drink is one that is freshly brewed. 

The Remedy

Always brew coffee just enough for you per time particularly when you are at home. This way you will always have a fresh sweet tasting coffee drink.

General Remedies to Common Coffee Mistakes

Sometimes, you might not be able to tell the reason your coffee tastes bitter. In this case, there are some remedies to correct the mistake. They include:

Bitter Coffee

Add milk or sugar to your coffee. You can also add a little amount of salt. This will extract the natural flavor of the coffee.

Watery Coffee

Nobody appreciates a watered-down coffee. A watery coffee can be caused by several factors like using water that is not hot enough for brewing, insufficient coffee, brewing too short, or smaller grind size.

To fix this, adjust your water/coffee ratio. Check your grind size, water temperature and brewing time. Then adjust accordingly.

Metallic Coffee

This coffee is caused by an issue with the quality of water used for brewing. Or build-up of mineral in your coffee making machine especially those who use tap water for brewing.

Always brew your coffee with bottled or filtered water.

Sour Coffee

This is caused by under extraction of coffee flavors and essential oils.  It usually occurs when your coffee is not brewed long enough. Or the coffee grounds are too big.

This can be solved by brewing the coffee a little longer or simply adjusting the coffee grind size to a finer texture.

Burnt Coffee

This usually occurs when your coffee beans are over roasted or when your coffee is overcooked. It can also occur if you use boiling water to brew for a long time.

Ensure you allow your coffee to get warm. When it stays too hot for a long time, its flavor is destroyed.


Plastic tasting coffee is commonly caused by coffee making machines. Coffee makers can cause this taste or flavor when they are overused, new or dirty.

Ensure that you regularly deep clean your coffee machine. This process is simple. Just wash the water reservoir and run hot water through the machine. You can also run a cleaning cycle with a 50:50 vinegar/water, baking soda/water or lemon/water.


Sometimes, the problem might just be the fact that we don’t like that coffee you brewed. Well, that should not be a problem. You can change your coffee recipe and explore other options until you find something you love.

There is no need to beat yourself over a mistake you made during brewing. If you remember what you did wrong, good; correct it. If you have forgotten, think back. It might be you missed a step during the brewing process, or you didn’t measure the right amount of water. 

Always remember to make notes when brewing your coffee in the future. Make sure you write down all the steps, the quantity/texture of coffee grounds, quantity/temperature of water used. Keep making adjustments until the problem is solved.

It takes skills and a lot of work to become a professional home barista. With constant practice and perseverance even when you do not get it right, you will be the best at it soon.