When it comes to making coffee, there’s not really a single “right way” to do things. This is due in part to the coffee drinker’s personal preferences. In the case of French press coffee, it’s a completely different method of preparation, resulting in a completely different beverage. The ratio of coffee to water makes quite a difference, it’s best if you experiment to find the ideal French press ratio for your personal preference.
You should experiment to find the best french press ratio for you
How full should a French Press be?
Since French press coffee is done with a manual pour-over and a filter plunger, you’ll want a coarser grind than with other methods. If your plunger doesn’t reach the bottom of your press, you’ll need to make a full pot all at once. Fill with coffee to just over the height of the plunger, fully depressed, and water to your max fill line (generally about an inch from the top). These limitations seem to be common among lower-priced presses. It keeps the coffee ratios consistent without much measuring required. “Eyeballing” works well with cheaper French presses for this reason.
However, if you’ve invested in a better press, the plunger is going to go all the way to the bottom if there’s no coffee in the way. It’s helpful to know what the proper ratios are to make sure your coffee stays just as consistent. (As a side note, there is a lot more customization possible with a good press, and it’s a good idea to spend the extra money for a higher-end model. It’s still going to be cheaper than most other methods.)
The Perfect French Press Ratio
Many people choose to start with a 1:10 ratio for their French press coffee. This means 400 grams (or mL) of water will need about 40 grams of coffee. For those coming over from standard drip coffee, you can use a similar ratio as you do in your drip machine. Keep in mind that the French press coffee will be stronger after brewing, as the coffee will be steeping for much longer. Unlike drip coffee, however, your French press coffee isn’t going to be as bitter. It’s going to contain all the volatile oils in addition to the flavor and caffeine.
If in doubt start with a 1:10 ratio; 1 gram of coffee per 10ml of water
As with any other manual methods of coffee preparation, you have full control over the resulting drink. Some choose to brew their coffee strong and mix with hot water after. This is particularly helpful if you’re not drinking it immediately after brewing. (In a French press, the coffee will continue brewing and cooling as it sits.) Others choose to use less coffee and let it steep for longer. This results in an even cheaper beverage, but it will lack the strength and smoothness that French presses are capable of.
We recommend starting with the standard 1:10 ratio of coffee to water and adjusting for your personal preferences. We also recommend keeping your coffee a bit stronger than you’d normally like it, and mixing with hot water. This makes it easy to customize for different preferences within your house. It also prevents you from ruining all those delicate flavors by reheating in your microwave. After all, you're using a French press because you want amazing coffee - and nothing amazing comes out of a microwave!
Once you've got ratio right you can move onto finding the best coffee for your french press