What Causes Bitter Coffee And How Can You Prevent It?

Several factors lie behind bitter coffee including the coffee bean, the brewing method, and water quality. Prevent bitter coffee using these tips.

What makes coffee bitter?

Well, there are several reasons including, the type of coffee bean, brewing method, and water quality.

If you use a cheap, low-quality, or stale coffee bean, it doesn’t matter how good your brewing method is, you will never get a good cup of coffee. That said, if you buy high-quality specialty coffee and the end result still doesn’t taste right, there’s a good chance that something is wrong with your brew method.

Let’s dig a little deeper into how bitter coffee happens and what you can do to fix it.

1. Over-Extraction
The most common cause of coffee’s bitterness is over-extraction

The most common cause of coffee’s bitterness is over-extraction, which essentially means that the coffee is over-brewed, adding flavors that you didn’t intend to the cup.

There are a few reasons over-brewing can happen. One of the most common is that the coffee is brewed for too long. There is a sweet spot for different brewing methods, and if you miss it, too many flavors are extracted, causing bitterness.

There’s not too much you can do about a drip coffee maker, but when you’re using a French press and you don’t push the filter down soon enough, the coffee often has a perceived bitterness.

2. Grinding the Beans Too Finely

Another cause of bitterness is grinding the beans too finely. The smaller the coffee grind, the faster the flavor is extracted. That’s why espresso uses fine grounds and cold brew uses coarse. If your ground coffee is too fine, they will release the good flavors too fast and start to give off the things that make it have that bitter flavor.

3. Using Water That's Too Hot

You can also over-extract coffee by using water that’s too hot. The ideal temperature is between 195 and 205 degrees F. The higher the temperature goes beyond 205, the more bitter the coffee will be.

You might think that too much water would make coffee weak, but it actually gives it a perceived bitterness. Why? Because each ground has access to more water than it needs to release its flavor, which allows the bitterness to escape.

How to Fix Bitter Coffee

How to Fix Bitter Coffee

There are a few things you can do to prevent bitter coffee. The first is to make sure you’re using high-quality coffee beans.

After you get the right beans, it’s time to focus on your technique, which means you have to figure out how to extract less. There are four main ways to do this.

1. Shorten Brewing Time

This one is pretty easy, but it depends on the brewing technique you use. For example, if you prefer a French press, press down the filter about 30 seconds earlier than you normally would. For a pour-over coffee, using larger grounds slows down the extraction time by letting the water pass through more quickly.

2. Use Cooler Water

If you want to be precise, use a thermometer to check the temperature of the water before pouring it over or using it in a French press. It might take a few tries to find the best temperature to get the results you want.

3. Grind the Beans More Coarsely

Again, larger beans let the water drain more quickly and don’t release flavor and bitter compounds as quickly, shortening the overall brewing time.

4. Use Less Water

This one is a little more difficult, but it means there’s less water for the grounds to access, resulting in better-tasting coffee.

Note that you should only try one of these fixes at a time. Too many changes too fast can take you in the opposite direction, and your coffee will be under-extracted and sour.

What Can You Do If You’ve Already Made a Bitter Cup?

Made a Bitter Cup

There isn’t much you can do to make a bitter cup of coffee taste good, but you can make it a little more drinkable by adding a pinch of salt directly to the cup. This won’t fix the mistakes, but it will take the edge off the bitterness so that you can drink the coffee, assuming you still want to.

Tools to Avoid Bitter Coffee

If you’re working on your brewing technique, here are a few things you can use to prevent bitter coffee.

Coffee Grinder

Hamilton Beach Fresh Grind Electric Coffee Grinder for Beans, Spices and More, Stainless Steel Blades, Removable Chamber, Makes up to 12 Cups, Black
  • EASY CLEANUP — DISHWASHER SAFE GRINDING BOWL: The grinding bowl on this coffee bean grinder is designed with durable stainless steel. It's removable for easy filling and pouring and is dishwasher safe.
  • GRIND ENOUGH TO BREW UP TO 12 CUPS OF COFFEE: If you love the delicious taste of coffee made from freshly ground beans, this electric coffee grinder is perfect for the job whether you're grinding coffee for a quick cup or a full pot
  • SIMPLE & INTUITIVE: The coffee grinder is so easy to use that you'll want to drink flavorful coffee made from freshly ground coffee beans everyday. Just place the lid on the grinder and press the button to grind coffee. Release to stop grinding.
  • DURABLE STAINLESS STEEL BLADES: With the durable stainless steel blades, this grinder makes easy work of grinding everything from coffee beans to herbs and spices.
  • REDUCE CLUTTER WITH HIDDEN CORD STORAGE: Hideaway cord storage at the bottom of the grinder stores the cord neatly and out of sight when it's not in use.

If you’re trying to adjust the size of your coffee grounds, the best way to do so is to grind them yourself. For that, you need a great coffee grinder, like this one from Hamilton Beach. It’s quieter than a lot of other models so you don’t have to worry about waking everyone up when making your morning coffee.

It grinds up to nine tablespoons of beans, which is enough for 12 cups of coffee. The grinding chamber removes for easy filling and cleaning, and the hideaway cord storage keeps it looking neat when not in use.

A Thermometer

KT THERMO Instand Read 2-Inch Dial Thermometer,Best For The Coffee Drinks,Chocolate Milk Foam
  • DESIGN:Multi-stage design of the fixed clip, adjust the thermometer read the location of the disk surface to facilitate observation of the temperature of the bubble.
  • MEASUREMENT IS SAFE AND SIMPLE: Can be directly and accurately measure the coffee drinks chocolate milk foam, foam temperature control.
  • MEASURING A WIDE RANGE: This Dial thermometer has a range of 0 degrees Fahrenheit to 220 degrees Fahrenheit, measurable boiling or frozen things.
  • EASY TO OPERAT:Compact stainless steel construction,easy to use and easy to clean.
  • SERVICE:Always be ready to respond within a 24 hour time frame.

This one is pretty simple, but you won’t know the temperature of the water you’re using unless you have a reliable thermometer, like this one from KT Thermo. It measures temperatures from zero to 220 degrees F which is just what you need to measure water temperature for coffee. The compact stainless-steel design is easy to use and it can be clipped to the side of the pot, so you can make sure your water cools down enough before pouring.

A French Press or Pour Over Coffee Maker

BODUM Pour Over Coffee Maker Grip, 8 Cup, 34 Ounce, Double Wall Cork
  • Does not trap essential oils of your Coffee in a paper filter, and makes a beautiful slow-brew
  • Includes a Permanent stainless steel mesh filter; no paper filters or capsules needed
  • Carafe is made of Borosilicate glass, which is more resistant to thermal shock than any other common glass
  • Double-wall insulation keeps coffee hot for hours
  • Cork grip stays cool, allowing comfortable, barehanded transport even when carafe is filled with hot coffee

A good French Press, like this one from Veken, or a high-quality pour over set, like this one from Bodum, also makes a big difference. The better the system, the easier it is to control the results. If you want to have complete control over your brewed coffee, a system like one of these will help you get there. If you like this post, check out our guide on the best non-bitter coffee.

Preventing Bitter Coffee is Easier than Fixing It

While adding a little bit of salt to a mug of bitter coffee might make it drinkable, it’s easier to learn how to avoid brewing bitter coffee in the first place.

Remember, the most important thing is to start with high-quality coffee beans. No matter what you do, you will never get a great-tasting cup of coffee from a bean that’s stale, cheap, or poorly roasted. From there, it’s all about technique.