You wake up drowsy eyed, craving warm coffee. You get dressed, gather your things, and prepare a big cup.

After much anticipation (because you read our article on circadian coffee rhythms and waited until 9:30am for your caffeine fix) you take a sip, only to taste bitter, acidic coffee. It tastes like you’re sucking on an old, wet cigarette. But how? You bought the $20 bag of beans from your local, award winning roaster who sources from a reputable coffee farmer. Where did it all go wrong?!

Well folks, we’re sorry to say this one might be on you. 9 times out of 10, a bitter cup is the result of a bad brew. So lets see how we can fix this:


Inconsistent Grind or Incorrect Grind Size

Depending on what type of grinder you use, you may have variety of grind sizes in your brew. Lower quality blade and burr grinders will grind inconsistently, leaving you with boulders and fines. This significantly alters how quickly your coffee extracts. Too many boulders will lead to under-extracted coffee – resulting in a sad cup of brown water. Too many fines will lead to over-extracted coffee and an overpowering, bitter cup.

This same logic applies to the overall grind size you choose for your preferred brew method. Each brew method has a grind size soulmate. Choose a grind size too big, and you under-extract. Choose a grind size too small, and you over-extract. Read our grind size post to learn what size is best for your brew methods.


Bean:Water Ratio

Similar to cooking or baking, brewing coffee requires a precise ratio of ingredients. Luckily there’s only two ingredients in this recipe – water and coffee. Make sure you’re not adding too much coffee, which will also lead to a bitter cup.


Burning Your Beans

Everything has a bitter, ashy aftertaste when you burn it- cookies, toast, hair etc. Coffee beans are no exception. If you burn them, they’ll taste bitter.

To avoid burning your coffee, it’s best to keep track of your water temperature. You’re aiming for a temperature range of 195-205 F. If you don’t have a thermometer or electric kettle to track temperature, it’s important to know that boiling water (212 F) will scald your beans. A good trick is to boil water, then take it off the heat for 30 seconds. This should bring your water temperature down into the 195-205 range.


Long Extraction Time

Although we’ve named a few ways you can over extract your coffee, here we’re talking about how long you let your coffee brew. The extraction time is however long you let your coffee grinds mingle with water. This variable also depends on your preferred brew method. A full immersion brewer like Duo Coffee Steeper takes 4 minutes, whereas other methods require different extraction times. Whatever brew method you use, take care not to extract for too long, as this will result in that bitter, wet cigarette taste.


Let’s recap. Here’s what to check for if you’re brewing a bitter cup:

  • Inconsistent grind size
  • Incorrect grind size
  • Wrong bean:water ratio
  • Burning your beans
  • Long extraction time

Keeping track of the variables above?

Think about trying a different or lighter roast – you may just not like this particular bean!