Why Is My French Press Coffee Bitter? +How To Fix It

A French press is a good and easy way to make your morning brew. You might want to get that little punch of bitterness in your coffee. But you don’t want to be punched in the tongue by a harsh bitterness. Having that problem when brewing coffee in a French press? Below you’ll find out how to fix that.

If a French press brews coffee that is too bitter, it’s usually because the grounds are extracted too much. Steeping the coffee shorter, using a slightly coarser grind, and using cooler water will reduce the bitterness enough in most cases. Coffee that’s roasted too dark can also be an issue.

A good hand grinder is not expensive and gives you a lot more control over the grind size and taste than pre-ground coffee. The TimeMore C2 (Amazon) is a hand grinder that provides amazing value for money and provides high grind quality.

There are a few more possible causes although they are less common. Keep reading below to find out what they are.

What Causes French Press Coffee To Be Bitter?

The key thing to understand is why coffee becomes bitter. The reasons are the same no matter what brew method you use.

Not sure how to exactly make good coffee in a French press in the first place? Click here for my step-by-step guide.

In most cases, coffee becomes too bitter when the extraction of the grounds is too high. What does that mean? A coffee bean consists of mostly a cellulose type material. The cellulose material doesn’t really do anything, it’s just basically plant building blocks.

In the bean there are also a lot of compounds and oils. Extracting those compounds and oils from the grounds is what coffee brewing is. You want to extract about 20%-23% of the weight of the grounds from the grounds and into your cup.

That 20%-23% is the sweet spot of extraction in most cases. That’s where you get the best tasting coffee. The compounds and oils in the coffee grounds don’t all come out at the same time. Some compounds take longer than others. The compounds that come out after 23% extraction are the compounds that taste very bitter.

You don’t really have to worry about the percentages. Just know that bitterness comes from extracting too much from the grounds.

While the basic cause of excessive bitterness in your coffee is the same no matter what brewing method you use, what you can change does change by brewing method. So when brewing in a French press, there are a few factors you can influence that will help you get a smoother, softer tasting cup of coffee. Here are the most important ones.

Man pushing French press plunger
  • Steep time: One of the biggest things that impacts how much you extract in a French press is how long you steep the coffee. The longer the water has contact with the grounds, the more time it has to extract. And as explained above, after a certain point, the results are not getting better. Try a 4 minute steep time.
  • Grind size: A French press should use medium-coarse coffee grounds. Most particles should be about the size of normal table salt. 15 grams of coffee that’s ground finer has more surface area than the same 15 grams ground coarser. More surface area means faster extraction. Pre-ground supermarket coffee is usually a bit too fine for a French press.
  • Fines: When you grind coffee beans, not all the particles will be the same size. Some will be bigger than ideal and others are smaller. Fines are the smallest particles that are hard to avoid unless you get a crazy expensive grinder. Coffee beans are dry and brittle so by breaking them up, you’ll always get some dust. That dust are the fines. And because they’re super small, they extract very quickly. In a bag of pre-ground coffee, these fines will usually end up in the bottom. So maybe it’s better to leave the last few grams in the bag and open a new one.
  • Push too hard: Don’t push down the plunger of your press too strongly. Push down to the point where you start getting more resistance and stop there. Compressing the coffee grounds will squeeze out more fines and also push out some more bitter compounds.
  • Water temperature: All those compounds and oils in the beans dissolve at different rates and different temperatures. The higher the temperature, the more chance of dissolving those bitter parts quicker. In a French press, aim for a water temperature of about 94 degrees Celsius. You don’t need a thermometer (although that’s a good way to improve constancy), just wait 30 seconds after the water has come off the boil (1 minute in a well-insulated kettle)  and you should have a water temperature that’s close enough. At least try to avoid pouring boiling water on the grounds.
  • Ratio: While the ratio of grounds to water usually isn’t too big of a factor for bitterness in a French press, it can play a role if you’re too far off. Try using more grounds to reduce the bitterness. This is a bit counterintuitive but it will reduce the total extraction. Read more about French press coffee/water ratio here.

Other causes

The changes above are all influencing the extraction. By reducing the extraction, you will get less bitterness in your cup. But what if you’ve tried the things above and it didn’t work. What can you do then? There are a few more things that can cause your French press coffee to be too bitter (for your taste).

  • Beans
  • Roast
  • French press filter

Make sure the coffee you’re using is of the Arabica variety and is fresh. There are two main types of coffee bean; Arabica and Robusta (there are many more but those two make up 99% of all coffee in the world). Coffee gets stale about 6 weeks after roasting. After that you can safely drink it but the taste will get worse.

Robusta beans have much more bitter notes in them and many people don’t actually like the taste of this type of bean much. Common tastes in Robusta beans are burnt rubber and leather. Not exactly appetizing. Arabica beans usually have a lighter, more floral taste.

Check your bag of coffee and if you can figure out what type of beans is in there. Most coffees will have it named somewhere. In blends Robusta is fine but if your bag has a significant amount (+-30% or more), try a bag that’s 100% Arabica and see if that makes a difference.

Of course getting whole beans that are freshly roasted is the best. Go to a local coffee shop that roasts its own coffee where you like the coffee. Usually they will sell the beans in small amounts to customers as well.

The type of bean has an impact but so does the roast. In general, the darker the roast, the more bitterness you get. Try a medium or medium-dark roast next time and see if that makes it better. In supermarket coffees, the roast level is usually not named. Many of those bags do have a strength level indicated though. That strength scale does usually correspond with the roast level.

Finally, the filter of the French press could be working less than optimal. If grounds get past/through the filter and make their way into your cup, those grounds keep being extracted. In a French press you can always expect some sediment in your cup. However, if it’s a lot and/or there are bigger pieces of coffee grounds, your French press might just be not working well.

The fix for that is easy though; Buy a better one. French presses are simple but if it’s not working properly, you’re not easily going to fix that. I’ve been using the TimeMore French press with a medium roast Arabica and I’ve never gotten too much bitterness or too much sediment in the cup. And it’s really affordable as well. Check it out below.

How To Make Your French Press Coffee Less Bitter

Above you can already find all the possible causes and the solutions. However, to make things crystal clear, here is a quick summary of the things you should try to fix your bitter coffee.

  1. Steep the coffee shorter: For a French press a steep time of 4-6 minutes is appropriate.
  2. Coarser coffee: If you’ve got a grinder, set it to a slightly coarser setting. If you buy pre-ground, find a coffee roaster locally that can roast fresh for you and can grind to the right size. For supermarket coffee, don’t use an espresso type coffee.
  3. Let the water cool down for 30 seconds to 1 minute before pouring into the French Press.
  4. Don’t push the plunger down too hard, try not to compress the bed of coffee at the bottom.
  5. Get 100% Arabica beans roasted medium or medium-dark.
  6. Make sure your French press actually filters out the grounds. You don’t want any bigger particles in your cup. Some sediment is normal for a French press though. If you get a lot of bigger coffee grounds, replace your French Press.

Favorite French Press Brewing Tools

Here are some things that help you brew better coffee:

  • French press: This beautiful stainless steel Meuller French press (Amazon) is high quality yet affordable and the double filtration system means less sediment in your cup.
  • Grinder: Fresh beans have to be ground. A hand grinder like the Hario Slim (Amazon) is affordable yet effective hand grinder that will improve your cold brew.
  • Scale: The amount of grounds you use makes a big impact on what your cold brew tastes like. A simple set of scales will makes your brews more consistent. I’ve been using this one (Amazon) for over a year with great success. Not the most aesthetic but effective.


Welcome to CoffeeImproved! Since falling in love with coffee, I've been on a journey to improve my morning cup day by day. That means I've tried many different brew methods, beans and equipment and experimented with all of them to find what I like. This is where I share what I've learned with you.

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