You buy a new bag of coffee, look forward to brewing it, take the first sip and find that it tastes unpleasantly bitter.
It is a frustrating experience, but it does not necessarily mean there is anything wrong with the coffee. In many cases, bitterness comes from the way it has been ground, measured or brewed.
Coffee naturally contains some bitter compounds, and a little bitterness can give a cup structure and depth. The problem is when it overwhelms everything else, leaving behind a burnt, dry or harsh flavour.
The good news is that bitter coffee is often easy to fix. A few small adjustments can reveal more sweetness, balance and flavour from the same beans.
Is Coffee Supposed to Taste Bitter?
Some bitterness is a normal part of coffee, particularly in darker roasts and strong espresso. It can sit alongside flavours such as dark chocolate, nuts, caramel and treacle.
Good bitterness should feel balanced rather than aggressive. It should not leave your mouth feeling excessively dry or make the coffee taste burnt.
If bitterness dominates every sip, one or more parts of your brewing process may need adjusting.
Your Coffee May Be Over-Extracted
Over-extraction is one of the most common reasons coffee tastes bitter.
When water stays in contact with coffee for too long, or passes through grounds that are too fine, it draws out more of the dry and bitter-tasting compounds.
This can produce coffee that tastes:
- Harsh or burnt
- Dry in the mouth
- Hollow after swallowing
- Strong but lacking sweetness
The quickest fix is usually to reduce the extraction slightly. You can do that by grinding the coffee more coarsely, shortening the brew time or using slightly cooler water.
Your Grind May Be Too Fine
Finer coffee has more surface area exposed to water, so it extracts more quickly.
If the grind is too fine for your chosen brewing method, the water can pull too much from the coffee before brewing is complete.
Try moving your grinder one or two settings coarser rather than making a dramatic adjustment. Small changes can make a noticeable difference.
As a general guide:
- Espresso needs a fine grind
- Moka pots usually need a medium-fine grind
- AeroPress recipes commonly use a medium-fine or medium grind
- Pour over coffee usually needs a medium grind
- Cafetières and cold brew need a coarse grind
Read our complete coffee grind size guide
Your Water May Be Too Hot
Water temperature affects how quickly flavour is extracted from coffee.
Using water straight from a rolling boil can make some coffees taste harsher, especially darker roasts. A practical starting point for most home brewing methods is around 90°C to 96°C.
You do not need a temperature-controlled kettle. Simply boil fresh water and allow it to rest briefly before pouring it over the coffee.
If your brew tastes bitter, try leaving the kettle for around 30 to 60 seconds before pouring. If it then tastes weak or sour, you may have allowed the water to cool too much.
Learn why water quality matters when brewing coffee
You May Be Brewing for Too Long
Leaving coffee in contact with water for too long can lead to over-extraction.
This is particularly common with cafetières. It is easy to become distracted and leave the coffee sitting for ten minutes when the intended brewing time was closer to four.
Once your cafetière has finished brewing, press the plunger and pour the coffee into your cup or a separate serving jug. Leaving it sitting with the grounds allows extraction to continue.
The same principle applies to filter and pour over coffee. If the water is taking much longer than expected to drain through the grounds, your grind may be too fine or the filter may be becoming blocked.
You May Be Using Too Much Coffee
A stronger cup is not always a better cup.
Adding more coffee without adjusting the water can produce a brew that feels heavy, intense and unbalanced. It may be perceived as bitter even if extraction itself is reasonably controlled.
For filter coffee, a useful starting point is approximately 60g of coffee per litre of water. That works out at around 15g of coffee for a 250ml cup.
From there, adjust gradually to suit your own taste. Measuring with a simple digital kitchen scale makes it much easier to repeat a good brew.
The Coffee May Be Roasted Too Darkly for Your Taste
Darker roasting develops stronger roasted flavours. Depending on the coffee and roast profile, this may bring out notes of dark chocolate, smoke, spice or caramelised sugar.
Some people love that intensity. Others experience it as burnt or overly bitter.
If your brewing technique seems right but you still find the coffee too bitter, try a medium roast with naturally sweet, chocolatey or nutty tasting notes.
A balanced blend can be a more approachable choice if you want plenty of body without an excessively dark finish.
Discover our BE AR House Blend
Your Coffee May No Longer Be Fresh
Coffee does not suddenly become unusable after a certain date, but its aroma and flavour gradually fade after roasting and once the bag has been opened.
As coffee loses freshness, the sweeter and more aromatic characteristics can become less noticeable. This can leave the roastier or more bitter flavours feeling more prominent.
Whole beans generally retain their character for longer than pre-ground coffee because less surface area is exposed to oxygen.
If you own a suitable grinder, try grinding only what you need immediately before brewing. Otherwise, choose coffee ground for your particular brewing method and keep the bag properly sealed.
Read our whole bean versus ground coffee guide
Old Coffee Oils Could Be Affecting the Flavour
Sometimes the coffee is not the problem at all. Old oils and residue can collect inside grinders, cafetières, reusable filters and coffee machines.
These oils become stale over time and can add a rancid or bitter flavour to otherwise good coffee.
Regularly clean any part of your equipment that comes into contact with coffee or brewed liquid, including:
- Grinder burrs and hoppers
- Cafetière filters
- Espresso machine baskets and group heads
- Reusable metal filters
- Bean-to-cup machine brewing units
- Coffee pots and serving jugs
Always follow the manufacturer's cleaning instructions, particularly when using cleaning products or descaling a machine.
How to Fix Bitter Coffee Without Changing Everything
When a brew tastes wrong, it is tempting to adjust several things at once. That usually makes it harder to work out what actually helped.
Instead, change one variable at a time.
- Keep the same coffee-to-water ratio.
- Grind slightly coarser.
- Brew again and taste the difference.
- If it is still bitter, shorten the brewing time slightly.
- Try slightly cooler water if needed.
Take a quick note of the grind setting, coffee dose, water amount and brewing time. You do not need to turn your kitchen into a laboratory, but a few notes make it much easier to repeat a cup you enjoyed.
A Quick Bitter Coffee Troubleshooting Guide
| What you taste | Likely cause | What to try |
|---|---|---|
| Harsh, dry and bitter | Over-extraction | Grind slightly coarser or shorten the brew |
| Burnt or smoky | Very dark roast or water that is too hot | Use cooler water or try a medium roast |
| Heavy and overpowering | Too much coffee | Use less coffee or add more water |
| Stale, flat and bitter | Older coffee or poor storage | Use fresher coffee and keep it properly sealed |
| Rancid or unpleasant | Dirty brewing equipment | Thoroughly clean the grinder and brewer |
Better Beans Make Better Coffee
Brewing technique matters, but the quality and freshness of the coffee still provide the foundation for every cup.
At BE AR Coffee, our coffee is roasted weekly to help provide customers with a fresh, flavourful cup. Our range includes smooth, balanced coffees that work across espresso machines, bean-to-cup machines, cafetières, filter brewers and other popular home brewing methods.
Browse our freshly roasted coffee collection
Try Before You Commit to a Full Bag
Finding the right coffee is personal. Some people prefer a rich, full-bodied espresso, while others want something smooth, mellow and naturally sweet.
If you are unsure which style suits you, our coffee samples let you try a smaller amount before ordering a full bag. Choose your preferred coffee and grind, then just cover the postage and packaging.
Final Thoughts
If your coffee tastes bitter, do not immediately assume you need a new machine or an entirely different brewing setup.
Start with the simple things. Grind a little coarser, reduce the brewing time, allow your water to cool slightly and make sure your equipment is clean.
Change one thing at a time and taste as you go. A small adjustment may be all that stands between a harsh cup and a coffee that is smooth, balanced and genuinely enjoyable.
Explore coffee standards from the Specialty Coffee Association
