While a great cup of coffee can set a positive tone for the rest of your day, a bad cup can easily have the opposite effect. One of the worst experiences is when your coffee tastes bitter and harsh.
Unfortunately, this happens more often than you might expect. However, bitter coffee isn’t something you just have to accept and deal with.
In this article, we discuss the common causes of bitter-tasting coffee and provide some simple solutions for how to fix it.
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Why Your Coffee Tastes Bitter
Coffee has a natural bitterness due to its caffeine content and the presence of certain organic compounds, such as chlorogenic acids.
While the term “bitter” often carries a negative connotation in the world of specialty coffee, a certain amount of bitterness can actually be a good thing.
Some bitter flavors, like grapefruit, dark chocolate, or cocoa, can add depth and complexity to the taste of your coffee. Where the issue arises is when this bitterness isn’t balanced with the sweet and acidic flavors also present in your cup.
There are two main reasons why your coffee tastes bitter:
During the brewing process, certain compounds are extracted or pulled from the coffee grounds but in a very specific order.
The fats and acids are extracted first and are what give the coffee its sour taste. Next are the sugars, which provide sweetness and balance to the overall flavor. Last to be extracted are the plant fibers, contributing the various bitter elements to the final brew.
If the brewing process happens too slowly, a higher percentage of the plant fibers make it into the cup, resulting in an over-extracted, bitter-tasting coffee.
2. Low Quality Beans
Cheap or mass-produced coffee will often taste overly bitter because it’s been over-roasted to mask defects and imperfections from subpar growing conditions or processing methods.
Additionally, while Arabica beans are more commonly used, particularly in specialty coffees, some coffees are made with Robusta beans because of their higher yields and lower production costs. These coffees, while inexpensive, can be excessively bitter and are generally considered to be of lower quality.
7 Simple Ways to Fix Bitter Coffee
The good news is if your coffee does taste overly bitter, there are some simple things you can do to fix it.
IMPORTANT NOTE: When trying any of the tips below, it’s essential that you only attempt one at a time and make small adjustments. Too much of any one of these can potentially swing you in the opposite direction, leaving you with a weak, sour cup of coffee.
1. Use a Coarser Grind
Grind size plays an important role when it comes to extraction.
For example, the finer the grind, the more surface area the water has to interact with during the brewing process. This allows the water to pull out a larger volume of compounds, resulting in an over-extracted, bitter cup.
HOW TO FIX: Start by following the grind size recommendation for your chosen brewing method. If your coffee still tastes bitter, try a slightly coarser grind. Continue to make small incremental adjustments until you have it dialed in.
2. Shorten Your Brew Time
The brew time refers to the amount of time water is in contact with the coffee grounds. The longer the brew time, the higher the potential for over-extraction and a bitter-tasting cup of coffee.
When using drip methods like pour-over, Chemex, or auto-drip, the brew time is primarily controlled by the grind size. The finer the grind, the slower the water is able to pass through the grounds, and vice versa.
HOW TO FIX: Start with the brew time recommendations for your chosen brewing method. If your coffee still tastes too bitter, reduce your brew time in 15-second increments.
3. Use Less Water
Your brew ratio, also known as your coffee-to-water ratio, is the amount of coffee used in relation to water when brewing. This ratio is essential to achieving the right balance between under and over-extraction.
The higher the ratio, the more water that comes in contact with the grounds, thus increasing the chance of more bitter compounds being extracted.
HOW TO FIX: A good starting point is the “Golden Ratio,” which uses 1 gram of coffee for every 18 grams of water. If your coffee still tastes bitter, try adjusting the ratio lower (use less water).
4. Reduce the Water Temperature
A common misconception when brewing coffee is that the hotter the water, the better. However, higher brewing temperatures can actually make your brew more susceptible to over-extraction.
The optimal brewing temperature for coffee is between 195°F and 205°F (90°C and 96°C). Going above this range can cause more of the coffee’s bitter compounds to be extracted, especially with darker roasts.
HOW TO FIX: When brewing a darker roast, aim for the lower end of the recommended range. Because these beans are less dense, they require less heat for proper extraction. For lighter roasts, stay towards the upper end to ensure you’re extracting as many of the tasty sugars as possible.
If you don’t have a thermometer, a general guideline is to bring the water to a boil and then let it cool for approximately 30 seconds to a minute for light roasts and two to three minutes for dark roasts.
5. Check Your Roast Level
Another critical factor influencing the bitterness of your coffee is its roast level. The darker the roast, the more bitter the coffee. This is most pronounced in French, Italian, and many espresso roasts.
HOW TO FIX: If your coffee tastes overly bitter, there’s a good chance you’re brewing a much darker roast than you may think. If so, switch it up and give a medium or light roast a try.
However, it’s important to note that the coffee industry lacks standardization when it comes to labeling roast levels. This means that what one roaster calls a medium roast, another might classify as dark.
This is especially true with large commercial roasters (national or regional coffee chains). More often than not, the actual roast level of their coffee is darker, thus more bitter, than what’s indicated on the label.
6. Buy Quality Beans
As mentioned earlier, bitter coffee can often be the result of low-quality beans, whether that’s due to the actual variety of the bean or because of how it was produced.
HOW TO FIX: Avoid the coffee aisle at your local grocery store and instead buy from specialty coffee shops or local and online roasters. These types of retailers are much more likely to offer high-quality, freshly roasted coffee beans.
7. Clean Your Equipment
Dirty brewing equipment is a common yet often overlooked cause of bitter coffee. Grinders are often the biggest culprit due to the residual coffee oils and old grounds that can accumulate over time.
If left uncleaned, these residues can become rancid and contribute to a bitter, unpleasant cup of coffee.
HOW TO FIX: Create a regular schedule for cleaning your coffee equipment. Doing so is one of the easiest ways to reduce unwanted bitterness and ensure a fresh, flavorful cup on each and every brew.
While a certain level of bitterness is both natural and a good thing in coffee, ultimately, the ideal amount comes down to personal preference. By utilizing the tips discussed above, you’ll dramatically reduce the chances of your coffee tasting overly bitter and be that much closer to consistently brewing a perfect cup.
Lastly, if you’d like to continue furthering your coffee knowledge or if you’re looking for ways to improve your home barista skills, be sure to check out our brewing guides and the coffee basics sections of our website.
Frequently Asked Questions
Bitter coffee often has a sharp, harsh taste that overshadows other flavors and may leave a lingering, unpleasant aftertaste on the back of your tongue. A simple test is to compare it to the mild bitterness of dark chocolate. If your coffee is more intense and not enjoyable, it’s likely too bitter.
Yes, adding salt to your coffee can reduce bitterness. However, we recommend using the tips discussed above before going this route. If you do decide to try this trick, make sure you only add a few granules at a time or you run the risk of ending up with a salty-tasting cup.
Actually, cold brew is typically less bitter than hot coffee, despite its longer brew time. The cold or room temperature water used in brewing extracts significantly fewer bitter compounds than hot water, resulting in a smoother, sweeter flavor profile.
Adding milk or creamer to your coffee can help mask its bitterness. The fats and proteins in these types of foods interact with the coffee’s bitter compounds, softening their impact on your taste buds. However, the underlying bitterness of your coffee won’t be completely eliminated, just less pronounced.