How to Make Strong French Press Coffee

Here at Robust Kitchen, we've been getting a lot of questions lately about how to make "strong" French press coffee.

But what exactly does "strong" mean to you? There are a few different ways people define a strong cup. 

Let's break it down so we can give you customized tips to get the bold brew you're after.

Some of you want a cup with more body and mouthfeel—one that isn't too watery. Your current French press leaves you wanting more aftertaste on your tongue. 

Others are looking for a more bitter taste, maybe something closer to what you get from diner coffee. And then there are those seeking a bigger caffeine kick—a bit more “buzz” in the morning.

Fear not, friends—we're here to help you achieve the strong cup you desire, no matter how you define it.

The Short Answer:

Usually, you can make your French press coffee “stronger” by 

1. increasing the coffee-to-water ratio—and/ or 

2. switching to dark roasted beans or beans with higher caffeine content, such as robusta or arabica robusta blends.

Higher coffee-to-water ratio and/or increased roast level often solve the issue for many definitions of strong. 

Now, let’s dig into what you mean by strong and how these two simple switches will get you there.

Coffee to Water Ratio

If a thicker, all-around more intense flavored cup is what you're after, upping the coffee-to-water ratio is a great place to start. 

Most recipes call for about 1 g of ground coffee per 15 ml of water, or a 1:15 ratio. But you can go bolder—try 1 gram of coffee for 12 ml of water for a ratio of 1:12. 

The higher concentration will give you a stronger extraction and fuller body in your cup.  (Gloess et al., 2013)

Note: This assumes you are using standard recommendations for your other variables such as a medium-coarse grind, a starting water temperature of ~200-205°F (94-96°C), and a brew time of around 4 minutes. (Wang & Lim, 2023)

In addition to more coffee grounds, choosing the right beans is also important here. Look for varieties from places like Sumatra in Indonesia—they tend to produce lots of natural oils that give a silky, almost nutty mouthfeel.

Roast Level + Preparation

Steer clear of ultra-lightly roasted beans, which can result in a thin, acidic cup, lacking those rich oils. Coarsely grind the oily, dark roast beans so the fats and sugars fully dissolve into your brew without getting trapped in the filter.

When it comes time to steep, let it go for at least 4 minutes before pressing. And stir halfway through—this agitation helps ensure an even extraction of those wonderful oils and body-building compounds.

While the bitterness may catch you off guard at first sip, lingering over the cup allows the complexity to unfold across your palate. 

In the end, the bold kick of darker roasted coffees should satisfy your craving for a strongly flavored brew.

When You Say Strong, You Mean…

Of course, making your coffee stronger depends on what you mean by strong.

Beyond, ratio, roast level, and preparation tweaks (agitating the coffee, extending brew time by a minute, and an ever so slightly finer grind)… the quality and type of bean you choose can also make a dent in the strength you experience. 

Stronger Mouthfeel 

If you're seeking a cup with a stronger “mouthfeel”—more body and richness with heavy, flavorful thickness on the tongue, start by using a medium-dark roast with natural oils already showing on the surface. 

Beans from origins like Sumatra and Sulawesi (affiliate link) produce coffees with the inherently syrupy mouthfeel you might be looking for. 

Grind these beans slightly coarser than normal so the rich oils can fully dissolve into your brew without getting trapped in the filter.

When it's time to steep, let it brew for a full 4 minutes, up to 5, before gently pressing down. About halfway through, give the grounds a gentle stir or swirl to help extract those flavorful oils. 

The agitation leads to a more even extraction while the extra time allows for full saturation.

Your French press coffee will have a velvety texture that coats the tongue. The result is a cup with a strong, luxurious mouthfeel you can truly savor.

Stronger Bitterness

If bitter is more your style though, turn to darker roasts with notes of smoke and chocolate. Look to origins in Latin and Central America—their beans often develop a robust bitterness during the roast at darker profiles.  (Blumberg, Frank, & Hofmann, 2010). 

Grind slightly finer than usual, but still coarse, then steep for a full 5 minutes without stirring. The extra minute, coupled with increased surface area, allows more of those intense dark roasty flavors to fully seep out.  (Wang & Lim, 2023)

Keep in mind this may be an acquired taste at first, but it should satisfy your craving for a strongly flavored cup with a bitter kick.

Stronger Caffeine Levels

Some of you just need an extra jolt of caffeine to power through your morning. For you, a higher ratio might not be enough—we need to up the naturally occurring caffeine content too. 

Robusta beans from places like Vietnam have approximately twice the caffeine of many arabica varieties.  (Olechno et al., 2021). 

So try a blend (affiliate link) of your favorite medium-dark roast with 10-20% robusta for a boost. 

Grind a hair finer than usual so more caffeine leaches out, but be careful not to clog the filter. 

You can also increase the coffee-to-water ratio here to 1:12, or even push it up to 1:10 for wire-you-up intensity. 

Just be aware this is a potent brew best saved for when you really need it!

Give it the standard 4-minute steep to fully extract those stimulating alkaline compounds. With the right robusta blend and higher coffee-to-water ratio, this cup will perk you up better than your morning energy drink ever could.

Additional Strong Coffee Tips

Regardless of how you define "strong," always use good quality filtered water for French press brewing. The high immersion time means minerals can leave unpleasant flavors if your starting liquid isn't pristine.

And don't forget proper technique—gently and slowly plunge the filter down once steeping finishes to avoid disturbing the grounds. Your well-extracted French press coffee should pour out clean and clear.

James’ Experiment

I decided to experiment with three different coffee-to-water ratios using my French press to personally see how it would impact the flavor and strength of the final brew. I used the same medium-dark roast coffee beans—an arabica from Thailand—for each test to control that variable.

For my first test, I used a standard 1:15 ratio which is what most French press recipes call for. This produced a nice, balanced cup of coffee with medium body and acidity. The flavor was pleasant, but I felt it lacked some intensity.

Next, I increased the concentration of coffee by using a 1:12 ratio of coffee to water. This resulted in a noticeably bolder and richer brew with a thicker mouthfeel coating the tongue. I detected much stronger hints of dark chocolate in the flavor. The bitterness was higher—but not an unpleasant bitterness.

Finally, I pushed the ratio even further using 1 gram of coffee for every 10 ml of water—a potent 1:10 mixture. Now the brew was intense. The first sip almost overwhelmed my palate with its extreme bitterness and dry finish. However, as I continued to drink, a noticeable complexity of flavors emerged that I hadn't noticed in the other brews—but this came at the cost of a more unpleasant bitterness.

In the end, I preferred the middle 1:12 ratio for its balance of rich flavor and full body without becoming overly intense. But I could see the value of using an even higher ratio when you need an extra caffeine kick—or if you associate a more intense bitterness with “strong.”

Final Takeaways

With a little experimenting using the methods above, we’re confident you'll achieve bold, intense cups tailored perfectly to how you enjoy your coffee. 

Feel free to adjust grind sizes, ratios, or steep times to suit your tastes as well. Part of the fun is finding your ideal "strong" brew. 

James

References

Blumberg, S., Frank, O., & Hofmann, T. (2010). Quantitative studies on the influence of the bean roasting parameters and hot water percolation on the concentrations of bitter compounds in coffee brew. Journal of Agricultural and Food Chemistry, 58(6), 3720-3728. https://doi.org/10.1021/jf9044606

Gloess, A.N., Schönbächler, B., Klopprogge, B. et al. Comparison of nine common coffee extraction methods: instrumental and sensory analysis. Eur Food Res Technol 236, 607–627 (2013). https://doi.org/10.1007/s00217-013-1917-xOlechno E, Puścion-Jakubik A, Zujko ME, Socha K. Influence of Various Factors on Caffeine Content in Coffee Brews. Foods. 2021; 10(6):1208. https://doi.org/10.3390/foods10061208

Wang, X., & Lim, L. T. (2023). Effects of grind size, temperature, and brewing ratio on immersion cold brewed and French press hot brewed coffees. Applied Food Research, 3(2), 100334. https://doi.org/10.1016/j.afres.2023.100334