4 Reasons Your Coffee Tastes Bitter

updated Dec 10, 2022
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There’s nothing worse than pouring a big cup of coffee to go with your breakfast sandwich, bringing it to your lips, taking that first sweet drink, and realizing that it’s bitter as sin.

Your cup of coffee should be a burst of good flavor, not an overpowering dose of bitterness. So why does it end up bitter?

Should Coffee Be Bitter?

It’s interesting that coffee is often associated with bitterness. While bitterness can play a role in a good cup of coffee, if you drink a really good cup, you’ll find that that bitterness is far from the dominant taste. Instead you get a variety of flavors, from floral to spice notes to chocolate notes. In fact there’s an entire flavor wheel dedicated to describing good coffee.

So if bitter is all you taste in your cup of coffee, there are several reasons why.

Why Coffee Tastes Bitter: The Technicalities

Coffee brewing is a science, and the main reason for bitter coffee is over extraction. Extraction is the process that pulls the flavor out of the coffee, turning clear water into that delightfully dark brew. When water mixes with the coffee grounds, a chemical reaction happens that dissolves flavor compounds. The trick is extracting the good ones, and not the bitter ones, which come out with more time.

With that in mind, here are a few things that could account for that bitter cup, and that you can easily avoid next time around.

1. You’re letting your coffee steep for too long.

This is especially common when making French press coffee, as many people have a tendency to leave the coffee in the French press even after they have pushed the plunger down. If you do this, the coffee will continue to extract, and next time you pour a cup, it will inevitably be more bitter than the first.

If you want to drink your coffee leisurely, transfer it immediately to a thermal carafe to keep it hot.

→ More on French press: How To Make French Press Coffee

2. You’re using the wrong grind size.

Grinding coffee beans changes how the flavor compounds dissolve, which means that if it’s too coarsely ground you risk under-extraction, and in turn a flat or perhaps a sour tasting coffee. But if they’re too finely ground, you risk an over-extracted, bitter coffee.

Different brewing methods will require different grinds, and sometimes you need to experiment to figure out the sweet spot, but if you’re getting a bad, bitter cup of coffee, chances are your grounds are a little too finely ground.

3. The water is too hot.

Water temperature plays a key role in coffee brewing, and if it’s too hot you’ll extract the bitter compounds. According to the National Coffee Association, 195°F to 205°F is ideal for optimal extraction. Water boils at 212°F, so in layman’s terms, that means not letting your water overboil, and letting it sit for just a minute before pouring over your grounds.

4. Your equipment is dirty

Over extraction isn’t the only culprit for bitterness. Residue coffee left over from the last time you brewed can definitely affect the flavor of future cups. Make sure you keep your brewing equipment nice and clean.

→ Clean your grinder! How To Clean a Coffee or Spice Grinder