What is the best grind size for French press?
For a French press, a coarse grind is recommended, but a medium grind is also acceptable. This grind size range will fall somewhere between 690-1300 microns(μm). Coarse grounds resemble small breadcrumbs and feel like sea salt in texture.
Using a coarser grind for your French press is essential because it allows for proper extraction during the steeping process. When you use a coarse ground, the coffee particles are less likely to pass through the filter, resulting in a cleaner cup with a full-bodied and well-extracted flavour. If the grind is too fine, it can lead to over-extraction and a muddy, bitter taste in your French press coffee.
Find the right setting on your grinder for your french press
Can I use pre-ground coffee in a French press?
Yes — you can use pre-ground coffee for a French press.
While grinding your beans just before brewing is ideal for freshness, high-quality pre-ground coffee can still yield a good cup. Make sure the grind size matches the French press requirements, typically medium - coarse.
Make sure to store your pre-ground coffee in an airtight container to maintain its freshness after opening.
Can I use an espresso grind or a fine grind for French press coffee?
No — An espresso grind size is much too fine for a French press, and will create extremely over-extracted coffee. It will taste very bitter, astringent and over-whelming. It will also clog up the metal mesh filter.
How about a medium grind for a French press?
If you prefer a stronger coffee, you can use a medium grind. This is finer than what most people brew with, but can create a good brew.
Make sure to decrease brewing time significantly, to avoid over-extracting the coffee.
What should I do if my French press coffee tastes bitter or sour?
Follow these steps to improve your coffee. They are in order of most to least effective — so if the first steps don’t work for you, trying going down the list until you identify what’s causing the bad taste.
If it tastes too bitter:
- Increase grind size — Use a slightly coarser grind for your coffee. A finer grind can lead to over-extraction and bitterness.
- Reduce Brewing Time — If your coffee brews for too long, it can over-extract bitter compounds and flavours that are normally harder to dissolve in water.
- Less agitation — If you stir or swirl your french press, then try lessening your movements or stop doing it altogether. Agitation speeds up the brewing process significantly, the same way sugar dissolves in hot water faster when stirred.
- Reduce temperature — Use cooler water, because hotter water increases the rate of extraction. Do this by waiting for water off the boil to cool, use a cooking thermometer, or use a kettle with a in-built thermometer.
If it tastes too sour:
- Reduce grind Size — If your coffee tastes sour, it may be under-extracted. Try using a slightly finer grind to increase the extraction of sweeter compounds.
- Increase brewing time — Increase the brewing time slightly to allow for more extraction. Start by adding an extra 30 seconds from your normal routine and adjust as needed.
- More agitation — Try stirring the coffee water slurry gently with a spoon to increase the interaction of the mixture. Don’t overdo it when trying for the first time, as you may over-extract the brew. Three or four stirs with a spoon should do it.
- Increase temperature — Cooler water can result in under-extraction. Try using water straight off the boil and see how it tastes — There is a misconception that boiling water burns coffee, but water cools very quickly after pouring so this is not a concern.
The best coffee to water ratio for a French press
We recommend a coffee to water ratio of 1:15 for a French press, but depending on how strong you want your coffee to be, your ratio can be anywhere between 1:12 for a strong brew and 1:18 for a weaker brew.
If your coffee tastes too strong:
Increase the coffee to water ratio. Using less coffee relative to the amount of water can result in a milder brew.
- Decrease the amount of coffee grounds you use while keeping the water quantity the same…
- …or increase the amount of water while keeping the coffee quantity the same.
If your coffee tastes too weak:
Decrease the coffee to water ratio. Using more coffee relative to the amount of water can result in a stronger brew.
- Increase the amount of coffee grounds you use while keeping the water quantity the same…
- …or decrease the amount of water while keeping the coffee quantity the same.
Why fines in your French press coffee are not a bad sign
Coffee fines are small particles of coffee that are produced during the grinding process. These particles are significantly smaller than the main coffee grounds and often resemble fine dust or powder.
Fines are desirable when creating drinks with strong body, texture and mouthfeel. The French press is a go-to brewer for creating this kind of coffee — for the same reason Turkish coffee and moka pots are favoured for their gritty texture too.
But if you don’t enjoy this texture, there are methods (listed in the next segment) to reduce it significantly.
How do I reduce coffee grounds from ending up in my cup when using a French press?
Use the correct grind size — Use a coarser grind for your coffee beans. This will help prevent small coffee particles from passing through the mesh filter.
Break and stir the crust — After brewing, gently break the crust that forms on the surface with a spoon. This crust contains lots of fines that can block the plunger and penetrate through the filter when pressing. By breaking and stirring, the grounds sink to the bottom of the brewer — the difference in resistance when pressing is quite substantial.
Plunge slowly — If you press the plunger down too fast, the fines are more likely to be forced through the filter. Rest your hand or hands on the plunger and press down gently — sometimes the weight of your arms is enough to do the work.
Avoid the dregs — The final liquid at the bottom of the french press will be saturated with coffee particles. Avoid drinking this if you don’t enjoy a silty textured cup.
Using a second filter — After brewing pour your coffee through a paper coffee filter or a fine-mesh sieve before drinking. This is more effort than the other tips, but it is a very effective way of eliminating coffee fines. There are also some paper filters specifically designed to be put inside a french press.