November 26, 2018

Is A Fine Grind Better For French Press Coffee?

French press brewing is one of the most simple and inexpensive methods to prepare coffee. Even a complete newcomer to coffee can follow the method and produce a decent cup. But can you turn a decent French press coffee into an exceptional one by using a finer grind?

It may seem against everything we know, but take a look at why using a finer grind in a French press could make sense.

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coffee brewed on french press

A French press of coffee ready to be poured. Credit: Izzy Rivi

An Unchallenged Method

The specialty coffee world is used to tweaking extraction time, grind size, and other factors to get the perfect cup. But we usually do this with pour over, espresso, and AeroPress methods of brewing. The humble French press has been a little overlooked.

It’s generally agreed that a French press is best used with coarsely ground coffee and water just under boiling temperature. Allow three to five minutes of immersion time, and you have a decent cup of coffee.

Of course, all three variables in this method can be tweaked. And all three factors also affect one another, so if you change one, you should consider the other two.

Pouring coffee into a cup. Credit: Izzy Rivi

Why a Coarse Grind Is Usually Used

It may seem strange to buy an expensive burr grinder only to pair it with a French press. But if you want great coffee, you should consider it. A quality grinder will produce consistently ground coffee.

Inconsistent grinds contain a range of particle sizes. A low-quality grinder can produce a lot of fines that coffee sieve producer KRUVE likens to coffee dust. Too many of them can create muddy or bitter coffee.

When you use coarsely ground coffee, it is less likely to contain fines. This means that you’re less likely to have a cloudy cup with muddled flavors. Using a quality grinder and coffee sieve, can solve this issue with using more finely ground beans.

Breakfast with a French press. Credit: Ana Valencia

The French press is an immersion method of brewing, which means that the beans extract for longer than in other methods. Because of this, we usually use a coarser grind to slow extraction and avoid over-extraction.

In a pour over, a finer grind can impede water flow. This isn’t the case in a French press, so we can experiment. We’ll consider the brew time if we adjust the grind size to avoid over-extraction. But we aren’t limited by the need to be sure that water can pass through grounds.

You may also like Understanding Coffee Extraction For Your Perfect Cup

cup of black coffee

A cup of black coffee. Credit: Ben Kolde

The Argument For Finer Grinds

Less coarse grinds allows the faster extraction of flavor-producing compounds. Because there’s more surface area, soluble compounds are quickly extracted from the beans into the water.

Matt Perger is the founder of Barista Hustle. He says that “grind size doesn’t change what’s being extracted. It only changes when the things are extracted. All of the flavour is there ready to be extracted. Grind size just puts more or less of that flavour in front of the water right away.”

coffee beans and kruve sifter

Coffee beans before being ground and sifted. Credit: Kruve Inc.

Matt highlights that “if you give water more contact time with the coffee, it will extract more flavours.” We can do this by extending the brew time, but because the water will cool, it may be less effective than using the same amount of time with a finer grind.

One of the fears of using finer grinds is that the coffee will end up cloudy or silty. You may think that finer coffee will seep through the filter screen. Quality French press pots have a screen fine enough to retain medium-sized grounds and coffee expands when saturated.

pouring coffee on cup from stainless steel french press

A stainless steel French press. Credit: Farsai Chaikulngamdee

James Hoffman is the author of The World Atlas of Coffee. He advises using medium ground coffee, stirring after four minutes, and then letting it brew for five to seven minutes. He says that “the French press is one of the most tolerant ways to make coffee. A long infusion time makes it easy to get a good extraction.”

“I’d recommend that people experiment with going finer each time. The coffee will get better and then hit a wall of bitterness. At this point, you’ll need to go coarser and you’re going to be getting the most out of the coffee.”

There is a point of over-extraction. If you go too fine, you can create a with coffee that’s extracted too many bitter compounds and is unpleasant to drink.

cold drinks and french press

A French press and iced drinks. Credit: Anshu A

How To Use Finer Grinds

This is the method I recommend as a starting point for your own experimentation with grind size.

The Coffee

Use 35 g of beans for every 16 ounces (just under 475 ml) of water. James’s method includes using a digital scale to make sure you know exactly how much coffee and water you are using and can adjust as needed. Grind your coffee medium to medium-coarse, using a quality grinder.

If clear coffee is important to you, try coffee sieves to remove the fines and boulders (the large particles). I found that I could reduce the steeping time by using 600-micrometer and 800-micrometer sieves. The largest particles had been removed, which meant more consistent extraction. But I felt that I wasted too much coffee this way.

pouring coffee into cup

Pouring from a French press. Credit: Nik MacMillan

The Method

In your first trials, use water that is just off the boil (around 200° F or 93℃). You can do this by boiling water and waiting around 30 seconds for it to cool a little.

After stirring the coffee and water to agitate it, cover the beaker with the lid and insert the plunger a little. It shouldn’t touch the coffee. Water cools quickly in a glass beaker, so the lid is just there to insulate the brew during extraction.

After seven to ten minutes, almost all of the coffee particles will have sunk. Keep an eye on this and make a note of when you’re ready to push the plunger. Then do this very slowly, to avoid stirring up the fines.

Enjoying a French press coffee. Credit: Rachael Gorjestani

Leave a tiny bit of space between the grounds and the screen. After this point, we are just letting the grounds become saturated enough to sink and avoid a sludgy brew. Turkish coffee uses the same concept.

Pour carefully to avoid disturbing the grounds and leave the last few sips in the pot, under the screen. You don’t want to drink this silty part.

Now repeat the whole method again with finer grinds and see if you notice a difference.

Matt Perger tells me, “For best results with a French Press, grind finer than you’ve ever ground before. Then go two notches finer.”

coffee brewing on french press

The French press is an easy and affordable brewing method. Credit: Ana Valencia

Adapting Water Temperature For Finer Grinds

When you adjust grind size, you should also consider the water temperature. Because a finer grind has more surface area, it will extract more quickly. Lowering the water temperature can slow the extraction and help avoid bitterness from over-extraction.

When using a medium grind, we can lower the temperature of the water from the recommended 200°F (93℃). By using water around 195°F (91℃) and brewing a little longer, we can get a cup that is bold enough but avoids the bitter notes of over-extraction.

If we lowered the water temperature with a coarse grind, we might get an under-extracted cup unless the brew time were extended to compensate. The key point here is that all the factors involved affect one another. If you change one, you will likely need to change another.

Even a complete newcomer to coffee can follow the French press method. Credit: Ivan Calderon

But some people prefer to brew with boiling water. Matt Perger says, “I’m a big fan of boiling. You can’t mess it up, and if the coffee is good you shouldn’t be ‘burning’ it or anything silly like that.”

There are so many different ways to brew coffee that it’s most important to understand the concept of extraction and play with it. It’s a matter of balancing the variables to find your perfect method. Try different water temperatures, grind sizes, and brew times and see what works for you.

cup of coffee and copper french press

Coffee brewed in a copper French press.

Which Kind of French Press?

It’s also worth mentioning that the standard glass French press beaker doesn’t maintain a constant brewing temperature.

If you’re serious about playing with variables and finding the best method, try a ceramic pot or add an insulation layer to your glass pot. Stainless steel pots provide good insulation, but I find that they add a subtle taste to my cup that I dislike.

A French press and roasted coffee beans. Credit: Sonny Ravesteijn

Understanding extraction can open a world of experimentation in brewing. And the French press allows for just as much innovation as other methods.

If you use a decent grinder, allow your grinds to saturate, and press the plunger slowly, you shouldn’t have a problem with silty coffee or muddy flavors.

Don’t be afraid to experiment by adjusting each variable. Adjust the grind size, water temperature, and brewing time and keep notes on what works and what doesn’t.

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