The one thing that can surely disrupt a perfectly good morning is a sour cup of coffee. Hitting your palate with a distasteful brew can leave you cranky and disgruntled. After all, you need a morning fix that’s fresh and has the right amount of zing to get energized and face the day.
The primary reason why your coffee tastes sour is under-extraction. A change in your coffee blend could also be the reason behind your sour coffee. Using fresh coffee beans, grinding your beans a little finer, and ensuring the perfect water-to-coffee ratio can make your coffee less sour.
Making a perfect cup of coffee requires special attention and care. One wrong move and your delicious brew can turn into a mouth-puckering, sour drink. Let’s look at what can cause your coffee to turn sour and what you can do to fix it.
What Makes Coffee Taste Sour?
Having a sour-tasting coffee isn’t an experience that you want to repeat. In order to avoid another sour cup, let’s look at what the causes might be. They include:
Under Extraction
When hot water is added to coffee, it releases sugars, oils, acids, and plant fibers to create a great-tasting brew. This is known as the extraction, or coffee brewing, process.
In this process, acids are the first things that are extracted. They can make your coffee taste quite sour. As you brew for longer, these acids are balanced out by oils, sugars, and other flavors to ensure a coffee taste that’s just right.
If your coffee isn’t brewed long enough, all the flavors in it won’t dissolve properly to provide you with a cup of coffee that’s well-balanced. This is under extraction, and it’s one of the most common reasons of sour-tasting coffee.
Under extraction is typically caused by one of the following:
Coarsely Ground Beans
Compared to large grounds, fine coffee grounds extract quickly, as it takes less time for the water to reach the center of each particle. It takes longer for coarsely ground particles to fully saturate, which is required for a balanced extraction.
If you use a burr-grinder with multiple settings, like the Cuisinart DBM-8 Supreme Grind Automatic Burr Mill (on Amazon), you may simply have the wrong grinding settings! Experiment with making the grounds more or less fine to help figure out if this is your issue.
Not Enough Brew Time
You might not be brewing your coffee long enough to bring out its true flavor. A short brew time may result in partial extraction of sweet flavors from the coffee beans.
You may have poured the water too quickly while using the pour-over coffee dripper. Or if you’re using a French press, you might have plunged down the filter too early.
Water Isn’t Hot Enough
The perfect water temperature for coffee is between 195 and 205 degrees Fahrenheit. If the water for your coffee is below this temperature, you won’t be able to extract the good stuff from the coffee.
Coffee to Water Ratio Is Off
A correct coffee-to-water ratio is essential to extract a balanced brew. Not providing each coffee ground with the right amount of water or not adding enough coffee to the water can result in under extraction.
Under-Roasted Beans
Perfectly roasted beans are critical for a good-tasting coffee cup. Green coffee beans are passed through the roasting process before they can be used to brew coffee. During this process, the coffee beans go through the Maillard reaction.
It is this reaction that caramelizes the sugars present in green coffee beans and transforms the raw organic compounds into delicious flavors. Coffee beans that are roasted too lightly may not experience the Maillard reaction and make your coffee taste earthy and sour.
Stale Coffee Beans
As time passes, your coffee beans start to lose their aromatic oils and the sugars break down, causing the once-delicious natural acids to become sour. While coffee beans can last for months, your coffee will gradually lose its well-balanced flavor within a month of being roasted.
After a few weeks, it’ll be pretty sour. And if the flavor turns lemony, it means that your coffee beans are completely stale.
How Do You Fix Sour Coffee?
Now let’s look at some remedies that can help fix the sour taste of your coffee:
Fine Grind Your Beans
A smaller grind ensures better extraction in less time, as the hot water will have to interact with a smaller surface area.
Smaller grounds are also helpful in pour-over methods, as water drains slower, which increases the brew time.
Extend the Brewing Time
Extending the brewing time by a few seconds can also help take care of this issue. Allow the hot water to interact with your coffee grounds for longer to ensure a perfect balance of bitterness and sweetness in your coffee.
If you’re using a French press, wait 10 to 20 seconds more before you plunge down the filter. For pour-over coffee, simply pour the water more slowly to avoid under-extraction.
Check the Water Temperature
The extraction rate of your brewing coffee is directly related to the water temperature. The hotter the water, the faster the extraction. If you keep the grind size and brewing time the same and just increase the water temperature, your coffee will taste less sour.
A water temperature of between 195 and 205 degrees Fahrenheit is best for your coffee.
Add Extra Water
Adding a little more water to your coffee means that each ground is completely submerged to ensure proper extraction
If you add a little extra water to your pour-over coffee, it increases the brewing time, since it’ll take longer to pour over the additional water.
Check Your Recipe
In most brewing methods, the coffee-to-water ratio helps determine your coffee’s strength. However, if you don’t use enough coffee, it could cause under extraction.
If you’re making coffee by following a recipe and measuring the water and coffee carefully, there’s a strong chance that this isn’t your primary issue.
However, if you’re using a new brewing method, you might be mixing up the correct water to coffee ratios, which could cause under extraction. You can easily take care of your sour coffee problem by adding water to your recipe.
Use Fresh Beans
Over time, your coffee beans lose their original flavor and may cause your coffee to become sour. Make sure that you use fresh coffee beans, as this ensures the best taste.
It’s best to try one solution to sour coffee at a time, as too many changes can result in over-extraction. Start with small changes before doing anything drastic. Sometimes, it may take a couple of changes before you can find that balanced taste of coffee again.
Sour vs. Bitter Coffee
The extraction process helps to draw out compounds like acids, oils, sugars, and plant fibers from your coffee. These compounds are responsible for the taste of your coffee.
When you add hot water to your coffee grounds, fats and acids are the first compounds that are extracted. They make your coffee taste sour.
Next, sugars are extracted, leading to a sweetness that typically balances out the acidity. Plant fibers are the last to be extracted. They add a bitter taste to your coffee and can smooth out the acidity.
It’s evident that if you stop the extraction process too soon, it can make your coffee turn sour. Over-extracting it, on the other hand, can make it overly bitter.
How to Grind Your Beans Better
Grinding your beans finely means that you’ll need less time to extract the best flavor from your coffee grounds.
Even if you change nothing, finely grinding your coffee beans can help remedy the situation. Smaller grounds are also better for use in pour-over methods, as water is drained slowly, which increases the brewing time.
Finding the Perfect Coffee to Water Ratio
It’s a well-known fact that water temperature has a direct effect on the rate of coffee extraction. Many people are aware of this because although hot coffee typically takes a few minutes to brew, cold coffee, which is made from refrigerated or room temperature water, can take a couple of days to brew.
Hot water ensures faster coffee extraction, so even if you keep the other variables like the grind size and brewing time the same but increase the water temperature, your coffee will taste less sour.
The ideal water temperature of between 205 and 210 degrees Fahrenheit will ensure coffee extraction that includes plant fibers and sugars to balance out the sourness of your brew.
The highest temperature for boiling water is 212 degrees Fahrenheit, after which it turns to steam. If you’re already using boiling water, then you can’t increase the water temperature any higher and will have to look for another way to reduce your coffee sourness.
Determining Your Taste Preferences
The reason behind the sour taste of your coffee could be just taste preference. If you typically drink dark roasts, then you might find the fruit notes of a light roast to be a bit sour.
If this is the case, either stick to dark roasts or gradually change from dark to medium before switching to lighter coffees. This is the best way to enjoy the full spectrum of coffee flavors.