But it’s the humble French Press (also, more commonly and tragically known as ‘a coffee plunger’), that is a mainstay in homes around the world. Although simple, it allows you to create an excellent cup. The device is easy to come by, easy to use and easy to clean. The French press is undoubtedly an under-rated champion in the coffee kingdom, even local coffee wizard, ‘Doctor’ Mario says so.
Each of these coffee gadgets define what extraction variables you can tweak. By limiting some, we have the ability to play with others.
The Chemex for example uses a thick, fine paper filter to ensure brewed coffee drips through slowly. This means you can’t tweak the time the coffee and water are in contact but you can control other things: grind size of coffee, the ratio of coffee to water, temperature of water, turbulence and technique. Since the time of dripping is always roughly the same, we can focus on controlling the controllable variables.
Limitation is a good thing.
The French Press brews through ‘immersion’. It is merely a canister with a filter. It does not use pressure like espresso, stovetop, siphon, or aeropress. It does not use fine paper filters like Chemex or V60; it does not require technique like espresso, Chemex, V60, Siphon. It just steeps, like tea. Simple.
Balance is always needed however. Even a French Press can be over- or under- extracted and it can also be too strong or too weak. Understanding and tweaking the variables of extraction allow us to get a desirable brew. We can change elements of the water (time, temperature, turbulence) or of the coffee (blend, roast, grind, ratio). Doing any will affect the resulting extraction, and thus your enjoyment of the brewed coffee.
This post will explain how you can make a perfect French Press. And we’ll be sure to call it a French Press, because a plunger sounds like it belongs in the bathroom.
How to Make the Perfect French Press
1. Choose the right coffee for the job
This is the most important step. Your brewed coffee will only be as good as the beans you start with.
Blend or Single Origin:
The French Press is a perfect device for sampling Single Origin Coffee (because it is very similar to SCAA cupping protocol). Single Origin coffees have unique characteristics or particular flavours. They’ll often come with a set of flavour notes (which I swear, if you go and calibrate your palate beforehand you’ll know it’s not just gibberish). Use a single origin if you want to enjoy the range of flavours present in coffee.
Blends give consistency and a more rounded flavour. You’ll still experience lots of variation between blends. Use a blend if you’re after a standard flavour to enjoy with lots of people i.e. in an office or plan to drink this coffee with milk.
As a rule, just don’t buy supermarket coffee. Instead get your coffee from your local roaster and ask them for recommendations on what coffee to use. Or have a wee hunt around online.
The roast degree will most likely be dictated by the coffee, but knowing what to look for will help you in your quest.
You want a light to medium roast if you’re going to drink this coffee without milk, a medium roast if you’re going to put a bit of milk in it. I don’t recommend using a darker roast for immersion brewing.
Coffee has inherent sweetness that is roasted out when roasted dark. Often, the only reason we need milk and sugar is to cut through bitter, ashy flavours, which is a sign of over-extraction or dark roasting.
Single Origins will almost always be roasted light to medium so they’ll be perfect for French Press.
(A disclaimer: If you’re after ‘bitter’ or ‘strong’ coffee, this isn’t the right recipe for you.)
2. Weigh and Boil: 1:16 ratio and 93°C water
We’re going to be using a ratio of 1:16. That’s 1 part coffee to 16 parts water. If you prefer stronger coffee, or plan to put in milk then use 1:14 and don’t change any other variables. There’s a footnote about strength and extraction at the bottom of this page*.
Here are the ratios in grams and mls for 1-4 cups of coffee:
1 cup: 15g + 240ml
2 cups: 30g + 480ml
3 cups: 45g + 720ml
4 cups: 60g + 960ml
Boil the water. You’ll be pouring it when it’s just off the boil, around 93°C (this is when it’s no longer making noises in the kettle)
Grind size determines the surface area of the coffee. More surface area (finer grind) will mean coffee is absorbed into water faster and less surface area (coarse grind) will mean coffee is absorbed into water slower. A delicate balance.
For French Press you’ll be looking at a grind size slightly coarser than “filter grind”, like, between ‘filter’ and ‘plunger’ on this grinder. (It’s hard to compare grinders as they each have different scales)
Spice grinders are terrible. Rotating blades simply smash the coffee beans, breaking it into uneven chunks with plenty of dust. This will give you a guaranteed over-extraction. You want a conical burr grinder. In this grinder, one part holds the coffee beans in place, the other part has several blades on an angle which shave even pieces off the coffee.
This Breville Conical Burr grinder is the best/cheapest model I know of, and it retails for around NZ$ 100 new.
Grind fresh, and only what you need as ground coffee oxidises within 15 minutes.
4. Wet. Pour. Wait 4 minutes.
First, rinse out your French Press (because, let’s be honest your house mates haven’t cleaned it properly.)
If you’re using a weigh scale put the ground coffee in the French Press, tare the scale, and then pour a tiny amount of water over the grounds till they’re all lightly covered. Around 2ml per gram of coffee will be sufficient.
You’ll see the coffee bubbling up, this is called blooming. There’ll be more if the roast is fresh. Let bloom for around 30 seconds. Tare the scale again.
If you’re not using a scale, you can measure your water in a measuring jug before pouring it in. Add the rest of the water.
Pour gently, covering all grinds.
Start a timer, wait 4 minutes.
Note: the water used to ‘wet’ does not contribute to the ratio.
5. Swizzle. Press.
It’s time. Give your French Press a light swizzle. A swizzle is a full rotation to re-cover the grinds that are on the top. It creates a bit of turbulence and breaks up the crust.
Then, a gentle press.
When plunging, you’re not trying to put pressure on the coffee, you’re simply filtering grinds. Doing it gently prevents them from slipping up the sides.
Pour. Drink. Enjoy.
Pro-tip: Cleaning. Don’t use detergents, instead half fill the plunger with hot water and pump the plunger up and down rapidly. Repeat a few times. You should take it apart and clean between the filter every now and then too.
- Grind your own beans, at filter grind.
- Use ratio 1:16
- Pour water just off the boil (93°C)
- 4 minute brew time
*Strength vs. Extraction.
Put simply, strength is the concentration of solids dissolved into the liquid and extraction is the amount of solids that are dissolved into the liquid. Read more here. Under-extracted coffee tastes sour or too acidic, over-extracted coffee tastes bitter. Strength is more like the intensity and body of the brew.