8 Reasons Your Coffee Tastes Bitter—and How to Brew It Right

If you're a dedicated java drinker who savors every sip, it's essential to know how to make coffee taste less bitter—and more delicious. After all, nothing can hijack your perfect morning like a too-bitter brew. Even worse, if you don't get to the bottom of the bitterness, you may be destined for bitter coffee on repeat. We connected with coffee experts to learn why your cup of joe sometimes hits the wrong flavor notes—and how to fix it.

Bitter Taste Explained

To be clear, coffee already sits squarely in this key flavor sector, but adjustments may be required when bitterness edges out the joys of java. "Bitterness is a bad word in the coffee industry, but the secret is that all coffee is bitter—it's one of the things we love about it," explains Matt Falber, founder of City Boy Coffee, a Long Island City, NY-based roaster offering ethically sourced specialty coffees from over 50 countries. 

Coffee customers often perceive bitterness as a negative characteristic, describing it as a harsh, drying sensation, say Justin Kutz and Steve Janzen from DKK Brands, which owns and operates ESPRO, a company known for its French press coffee makers. "It is important to note and understand that caffeine, assumed to be flavorless, actually tastes bitter," says the two.

How Bitter Is Too Bitter?

Chocolate is also bitter, Falber says, adding that if you've ever accidentally made hot chocolate with pure cocoa, you've likely experienced bitter overload. 

Dialed back, the right amount of bitterness pleases the palate. "Bitterness can help focus taste on sweetness and acidity, which balances the elements for a great cup of coffee,” Kutz and Janzen explain. Falber concurs: "A balanced cup is what people are after, and what we all want to avoid is too much bitterness." 

Bitter vs. Sour 

Bitterness isn't the only flavor bedeviling your brew—if the beans are underdeveloped by a roaster, or the grind is too coarse, it can also hit a sour note. "Sour coffee is often the inverse of bitter coffee," Falber says.

Reasons Your Coffee Tastes Bitter

When your java jolt crosses the line from bitter in a good way to too bitter to swallow, several factors may be responsible—all of which can be easily resolved.

Over-Extraction

If it takes too long for the hot water to run through the grounds, the results may be bitter; if your machine brews it too quickly, it's under-extracted and may taste sour.

Try timing it: "If your coffee is too bitter, try setting a timer and seeing how long it takes to brew your coffee," Falber suggests. "More exposure to water typically means more extraction, and over-extraction can lead to too much bitterness."

Wrong Grind Size

Grind size is a major culprit of subpar results, Falber says. Coffee can be too bitter if ground too finely, but it can be sour if it isn't ground finely enough. 

Use a burr grinder: The right grinder can make you the master of your coffee universe. "A burr grinder will give you more control over the size of your coffee grounds," Falber says.

Roasting Time

Longer roasting periods can also portend bitterness. Light or medium-roasted coffee preserves more natural characteristics and subtle flavor nuances while imparting less bitterness than dark-roasted coffee, the experts explain. "Darker roasts have higher solubility, leading to a more bitter taste," Kutz and Janzen point out.  

Over-roasted: Over-roasted beans, they say, are also more bitter due to the increased presence of phenylindanes, chemical compounds that occur in darker roasts.

Inferior Water

Filtered water is crucial for taste, aroma, and body. At the end of the day, a cup of coffee is comprised of 98 percent water, and water's minerals greatly impact extraction. 

Use soft water: "Using quality soft water, such as distilled or reverse osmosis water, helps reduce mineral interference (calcium and magnesium), resulting in a cleaner, smoother, and well-balanced cup of coffee," Kutz and Janzen explain. They nix hard water, deeming it a poor solvent that can cause buildup in brewing equipment. 

Add a pinch of salt: A smidgen of salt added to coffee grounds or a just-brewed cup can help alter that bitter state. Salt can improve the extraction of your water if it's too soft, Falber says. Kutz and Janzen also consider it a great hack to counteract bitterness. "Adding salt to coffee 'tricks' our taste buds by enhancing our perception of sweet, sour, and umami flavors while decreasing our perception of bitterness," they say.

Water Temperature

The water temperature can also wield influence. "Light roasts require water that's boiling hot but you'll want a slightly lower temperature for a dark roast," Falber says.

Over-Steamed Milk

Attention latte and cappuccino lovers: Milk can also push espresso-based drinks into bitter territory. "Over-steamed milk can break down proteins, causing a bitter taste and poor texture," Kutz and Janzen say.

Brewing Method

Your brewing equipment and how you're executing your brew also play a role. "If you're using a manual brewer, take a look at your technique. How's your pour? Are you wetting all the coffee evenly?" Falber says. A French press, he adds, is a very forgiving brew method. "It's harder to over-extract coffee made in a French press," he says.

Bean Quality

Whether you use a French press, an espresso maker, a Moka pot, or an automatic coffee machine, the outcome still depends on whether you follow the directions in the machine's manual and your beans. "No matter how you brew your coffee, it will only ever be as good as the beans you start with," Falber says.

Kutz and Janzen suggest using high-quality, freshly roasted arabica coffee beans, then zeroing in on your preferred roast degree (light, medium, or dark). Then, continue to spread your coffee wings. "Try different coffees to keep your palate fresh," they suggest.