10% Off Gift Subscriptions Today — The gift that keeps giving

Why is my coffee bitter?

almost 2 years ago by Rebecca P.
Tags: brew trouble, brewing, education
2 responses
over 1 year ago
by Ryan F., Chief Coffee Schemer
Let's get to the bottom of your bitter coffee problem. Starting from the top [clever], here is a quick checklist for removing the bitter from your morning cup. 

Stale Coffee Beans
How old is your coffee? Is it pre-ground? As a general rule, whole bean coffee stays at peak freshness for about three weeks after it's roasted. After three weeks, the oils and sugars within the coffee bean escape, causing the flavor of the coffee to taste bitter. If you're using pre-ground coffee, the coffee can take on a bitter flavor 24 hours after it's ground. That's why we always recommend buying freshly roasted whole bean coffee and grinding it right before you brew.

Coffee Too Finely Ground
Grinding coffee too fine is a common cause of bitterness (also known as over extraction). How do you know what grind size is right for you? This often requires a little experimentation. The grind you use depends on how you make coffee. For an espresso maker or an AeroPress where the coffee grounds aren't exposed to water for a long period of time, you'll want to use a finer grind. For a pour-over brewing method where the grounds sit in water, such as a French Press or Chemex, you'll want to use a courser grind. For an automatic coffee maker, you'll want be somewhere in the middle.

Grounds Steeping Too Long
Using a French Press, don't leave the coffee grounds submerged in water for more than 4 minutes.  A classic French Press looks beautiful and might take you back to your adventures in Paris. However, you'll want to serve the coffee immediately after it's done steeping in the French Press to prevent your coffee from meeting a bitter (over extracted) fate.

Water Too Hot
195 to 205 degrees is the sweet spot for brewing coffee. Going old school, that's about 2-3 minutes off of boil. If your water is too hot or over boiled, you'll extract the bitter compounds from the coffee.

Roast Profile
Coffee preferences and tastes are very subjective. A coffee drinker who enjoys a darker roast will often label a lightly-roasted coffee with a more tea like or fruity tasting profile as bitter or tart. This isn't necessarily a brewing issue or imperfection with the coffee. 

I hope this checklist helps you diagnose the cause of your bitter brew. If not, please shoot me an email at ryan@beanbox.co. We're happy to help!
over 1 year ago
by Matthew B., Chief Coffee Wrangler
Beyond controlling for freshness, grind, roast profile, time, and temperature, there's a well-known psychological aspect to perceiving bitter coffee: the color of the cup. Our perception of taste comes not merely from the chemical aspects of what we consume and how those bear on our body's senses of taste and smell, but from our own mental state.

Turns our that white cups provide greater contrast for the dark color of coffee, and thereby predispose us to perceive stronger, and often more bitter, tastes from the coffee we're drinking. By contrast, using clear glass to drink from predisposes us to imagine that we're drinking something lighter and sweeter than we'd otherwise detect. The research on the effects of color on coffee taste is compelling, and I can personally vouch for the effects, not just in myself, but having observed hundreds of people at our tastings over the past few years.

As I have a tremendous sweet tooth, it should come as no surprise that my cup of choice is a clear, 5-ounce juice glass. No bitter mugs for me!

Related Questions

Why does coffee taste sour?

almost 2 years ago by Gregory V.
2 responses

Let's dig into some possible causes of the sour taste. One common cause is under extracting the coffee during the brewing process. This happens when not enough flavor is taken out of the coffee grounds... See full answer

Why does coffee taste burnt?

almost 2 years ago by Suni C.
1 response

There are three culprits to the burnt coffee taste so highly prized among gas station cafes: Coffee that's over roasted, or where the roast profile heats up too quickly. While some of us love a... See full answer

Can coffee go bad?

almost 2 years ago by Jeramy I.
1 response

Yes, yes, and yes. The "staling effect" in coffee is very well understood, but unfortunately that hasn't yet been recognized in the marketing and sale of most coffee in the United States. For a great... See full answer