The amount of coffee grounds you should use per cup or liter of coffee is often confusing. However, there are clear rules that are easy to remember and universally applicable. In this article, you'll read all about the correct dosage and brewing ratio, the best measuring method, and the universal recipe.
The dosage is no coincidence
The amount of coffee used is crucial for a balanced brew. Whether brewing a classic filter coffee , a French press, or an espresso , the right brewing ratio—that is, the amount of ground coffee used relative to water—enables good extraction. Extraction means that water separates the coffee particles from the ground coffee, which then determine the coffee flavor in the cup.
The less ground coffee we use, the less the water can dissolve. The degree of grinding of the coffee also plays an important role in the extraction efficiency, but we'll discuss this later.
Little coffee powder, lots of water – over-extraction
When we add a lot of water to a small amount of coffee and extract it for a long time, for example, in a French press, the water dissolves a large portion of the soluble coffee particles. The problem is that not all of these particles are tasty. The longer and more thorough the extraction, the more bitter the coffee becomes. Over-extraction leaves a dry, astringent feeling in the mouth, which is technically called "astringency."
The large amount of water also makes the coffee extremely diluted. Bitter, diluted, dry? Everyone knows that. Not at all tasty!
Lots of coffee powder, little water – under-extraction
If we add a small amount of water to a large amount of coffee, we get the opposite result. The small amount of water isn't enough to dissolve the desired amount of coffee particles. This is called under-extraction. Under-extraction is acidic and aggressive. An under-extracted espresso can also have a salty note.
Because of the small amount of water used, the final beverage also contains little water. While we extracted too little from the coffee grounds, it's still a lot compared to the amount of water. The coffee is therefore rather strong due to the concentration of dissolved coffee particles. The concentrated strength means concentrated acidity in the flavor due to under-extraction.
Both scenarios—too little coffee in relation to the water and too much coffee in relation to the water—have one thing in common: they are unbalanced. Acidity and bitterness are not in balance. Why? Something crucial is missing: sweetness! The inherent sweetness of coffee is crucial for its balanced and delicious taste.
So let’s go in search of sweetness, or as they say, the sweet spot.
Brewing ratio as the key to the sweet spot
Brewing coffee is neither rocket science nor voodoo. However, there are a few rules to follow when preparing coffee. One very important one is the brewing ratio, which varies depending on the beverage group.
The brewing ratio is the ratio between the amount of ground coffee used and water.
18 grams of coffee in relation to 300 ml of water results in a brewing ratio of 1:16.66
In other words, we can also say 6 grams of coffee to 100 ml or 60 grams to one liter of water. To represent the brewing ratio, the amount of water is divided by the amount of coffee used.
60 grams of coffee to one liter isn't a random example of a brewing ratio, but rather the standard recipe for all filter coffee methods. Whether you're brewing with the classic Melitta filter or a modern Hario V60 filter, an automatic filter coffee machine, or even a French press, 60 grams per liter, or 1:16.66, will work just fine.
How much coffee powder for filter coffee?
The dosage for filter coffee is not random, but ultimately a combination of the majority of people's preferred taste and mathematics. Filter coffee drinkers have a "perceptual expectation" born of habit and taste.
If a coffee beverage has a certain strength, we perceive it as filter coffee. This strength can be quantified, measured, and calculated.
Filter coffee tastes like filter coffee when it contains a strength of 1.10%–1.5% dissolved coffee particles. The rest is water, or about 98%.
To achieve a balanced brew of this strength, we need a brewing ratio of at least 1:20 and a maximum of 1:14. This equates to a coffee quantity of between a minimum of 50 grams and a maximum of approximately 72 grams per liter. In the video above, I even mention a brewing ratio of 1:12 as the strongest concentration. However, this requires a bypass to reduce the strength.
So how much coffee powder per 100 ml? Between 5 and 7.2 grams.
An average coffee cup holds 150 to 200 ml of liquid. The dosage should be calculated accordingly.
How much coffee powder for espresso?
Espresso is a small, strong drink. Under pressure and heat, a large quantity of coffee particles are extracted from a small amount of coffee grounds.
Espresso also triggers a taste perception in the coffee drinker. A classic espresso has a concentration of at least 7% dissolved coffee particles, meaning around 93% is water. Strong espressos reach double-digit concentrations of 10 or even 11% coffee particles.
To achieve a strength of at least 7%, a brewing ratio of a maximum of 1:3.5 is possible, for example 9 grams of coffee powder and 31.5 grams of liquid.
With espresso, the brewing ratio is more difficult to measure than with filter coffee. With filter coffee, the amount of water can be manually weighed and added. This isn't possible with a traditional espresso machine, as it is flushed directly from the brewing head over the espresso.
That's why espresso is measured by the volume of the brewed espresso. The ratio of brewed espresso to the amount of coffee used is called the "drink ratio."
Recommended ratio for a classic espresso:
1:2 which corresponds to 9 grams of coffee powder and an espresso weight of 18 grams
until
1:2.5, which corresponds to 9 grams of coffee powder and an espresso weight of 22.5 grams
Coffee machine inventions like capsule machines and fully automatic coffee machines have literally diluted what we know as a classic, strong espresso. These machines brew with a different proportion, and the strength of the drink changes accordingly. Nevertheless, both claim to brew "espresso."
This has a major impact on people's expectations of what an espresso tastes like. In coffee bars, more and more people are telling the barista that their espresso is too strong. This is due to changing habits and taste expectations.
Strength and extraction – the basis of a good brew
I explained the relationship between strength and extraction in a detailed video. Here's a brief summary. The balance between strength and extraction is essential for coffee to taste good.
Strength is the concentration of dissolved coffee particles. Every beverage has a very specific, characteristic strength.
We achieve this concentration by extracting coffee. Not everything we can extract from the coffee bean is delicious and desirable. We aim to extract within a narrow range. The target extraction range is 18–22%. Lower extraction results in the sour taste of under-extraction, and higher extraction results in the bitterness of over-extraction. The golden mean is balanced, sweet, and delicious. Hitting it precisely is what we call the sweet spot, where everything is in balance.
The extraction process for all coffee drinks aims for the same size, while the strength varies. This is logical, since we want to use only the most delicious parts of the coffee bean for all our coffee drinks.
In order to achieve different strengths and thus different coffee beverages, adjusted dosages are used.
Why a coffee spoon makes no sense
Unfortunately, it's impossible to always fill a spoonful the same amount. A few grams of difference can happen quickly and multiply with the number of spoonfuls. Using 9 grams of coffee per 100 ml for filter coffee instead of 7 inevitably leads to under-extraction and thus an unpleasant acidity in the taste.
Coffee also weighs and has a different volume depending on the roasting level and origin. A heaped teaspoon of a light roast coffee is significantly heavier than a heaped teaspoon of a dark roast coffee. Dark coffee has more volume but less density.
If you only focus on the amount of a spoonful, an inaccurate dosage is inevitable.
How big is a classic coffee cup?
A typical coffee cup holds about 150 to 200 milliliters. In restaurants, such cups are often used for cappuccinos. If you're expecting guests and need to brew a specific number of cups of coffee, I recommend calculating with 200 ml as a baseline.
So let's brew with the classic brewing ratio of 6 grams of coffee to 100 ml of water. We want 4 cups of coffee, so we brew 800 ml to 48 grams of coffee. For every gram of coffee used, 2 grams of water remain in the coffee cake. So we get a total of 800 grams minus 2 x 48 g of coffee, or about 700 ml of coffee, or about 175 ml per cup. Perfect!
The principle that 2 grams of water are absorbed into the coffee cake for every gram of coffee used only applies to filter coffee methods without pressure. Espresso and Aeropress coffees leave a different residue.
How many grams of coffee for the French Press
If you're having guests over for coffee, the French press is also a good option for brewing a larger volume of coffee. The French press, also called a plunger, is one of the alternative brewing methods. The water and coffee remain in contact throughout the entire brewing process. This is known as "full immersion."
I like to brew the French press at 7 grams per 100 ml. While the coffee is in contact with the coffee for a long period of 3-5 minutes, there's hardly any turbulence after the initial stirring, which is why the extraction is slower than with traditional filter-drip methods.
By using a higher dosage, I still get a sufficient strength in my coffee. At the same time, the extraction is slightly lower, resulting in a slightly more noticeable acidity.
With a French press, the plunger's metal mesh breaks up the extraction process and separates the coffee grounds from the coffee mixture. Unlike with a paper filter, coffee oils and some sediment remain in the coffee mixture. These oils and sediment result in a less transparent coffee flavor. The lower extraction rate and the associated acidity balance the flavor. A stronger extraction rate would increase the bitterness of the French press.
Conclusion on dosage
The amount of ground coffee to use for all types of beverages is more or less determined by the coffee's extraction capacity. This is useful because it provides guidelines to guide you.
Anyone who's experimenting with coffee and wants to try out different brewing methods has a huge range of options. Using our guide, you can first determine the exact dosage and then focus on other factors like the grind size or water temperature.
