The amount of coffee grounds one should use per cup of coffee or per liter often causes uncertainty. However, there are clear rules that are easy to remember and universally applicable. In this article, you'll read everything about the correct "dosage" and the appropriate brew ratio, the best measurement method, and the universal recipe.
Dosage is not a matter of chance
The amount of coffee used is the prerequisite for a balanced brew. Whether we're brewing a classic filter coffee, a French Press or an espresso. The appropriate brew ratio, i.e., the amount of coffee grounds used in relation to water, enables good extraction. Extraction means that water dissolves coffee particles from the grounds, which then create the coffee flavor in the cup.
The less coffee grounds we use, the less the water can extract. For extraction capability, the grind size of the coffee also plays an important role, but we'll address that elsewhere.
Little coffee grounds, lots of water – over-extraction
When we add a lot of water to a small amount of coffee and extract for a long time, e.g., in a plunger pot (French Press), the water dissolves a large portion of the soluble coffee particles. The problem is that not all of these coffee particles taste good. The longer and more extensive an extraction is, the more bitter the coffee becomes. So-called over-extraction leaves a dry, astringent feeling in the mouth, which in technical terms is called "astringent."
Due to the large amount of water, the coffee is simultaneously heavily diluted. Bitter, diluted, dry? Everyone knows this. Not delicious at all!
Lots of coffee grounds, little water – under-extraction
If we add little water to a large amount of coffee, we get the opposite result. The small amount of water is insufficient to dissolve the desired amount of coffee particles. We speak of under-extraction. Under-extraction is sour and aggressive. An under-extracted espresso can also have a salty note.
Due to the small amount of water used, the final beverage also contains little water. Although we've extracted too little from the coffee grounds, it's still a lot compared to the water quantity. So the coffee is stronger through the concentration of dissolved coffee particles. The concentrated strength means concentrated acidity in the flavor due to the under-extraction.
Both scenarios – too little coffee in relation and too much coffee in relation to water – have a common consequence: they are not balanced. Acidity and bitterness are not in balance. Why? Something crucial is missing: sweetness! The sweetness inherent in coffee is essential for it to taste balanced and delicious.
So let's search for the sweetness, or as it's nicely called, the sweet spot, in the Aeropress, the V60, and so many other brewing methods.
Brew 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 brew ratio, which varies depending on the drink category.
Brew ratio is the relationship between the amount of ground coffee used and water.
18 grams of coffee in relation to 300 ml of water results in a brew ratio of 1:16.66
In other words, we can also speak of 6 grams of coffee to 100 ml or 60 grams to one liter of water. To represent the brew ratio, the water quantity is divided by the amount of coffee used.
60 grams of coffee per liter is not a random example of a brew ratio, but the standard recipe for all filter coffee methods. Whether you're brewing a classic Melitta filter or a modern Hario V60 filter, the automatic filter coffee machine, or even the plunger pot – with 60 grams/1 liter or 1:16.66, you'll do well.
How much coffee grounds for filter coffee?
The dosage for filter coffee is not a matter of chance, but ultimately a combination of the preferred taste of the majority of people and mathematics. Whoever drinks filter coffee has a "perception expectation" that arises from habit and taste.
When a coffee drink 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. By the way, the rest is water, about 98%.
To brew this strength in a balanced way, we need at least a brew ratio of 1:20 and at most 1:14. Converted, this corresponds to a coffee ratio of between at least 50 grams and at most about 72 grams per liter. In the video above, I even mention a brew ratio of 1:12 as the strongest concentration. However, this requires a bypass to reduce the strength.
So how much coffee grounds 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 grounds for espresso?
Espresso is a small, strong drink. Under pressure and with heat, a large amount of coffee particles are extracted from a small amount of grounds.
Espresso also triggers a taste perception expectation in the coffee drinker. A classic espresso has a concentration of at least 7% dissolved coffee particles. So about 93% is water. Strong espressos reach double-digit concentrations of 10 or even 11% coffee particles.
To achieve a result of a strength of at least 7%, a brew ratio of at most 1:3.5 is possible, for example 9 grams of coffee grounds and 31.5 grams of liquid.
With espresso, the brew ratio is more difficult to measure than with filter coffee. With filter coffee, the water quantity can be manually weighed and added. With a classic espresso machine, this is not possible because it is dispensed directly from the brew head over the espresso.
Therefore, with espresso, we measure the volume of the brewed espresso. The term for the ratio of brewed espresso to the amount of coffee used is the drink ratio.
Recommended ratio for a classic espresso:
1:2, which corresponds to, for example, 9 grams of coffee grounds and an espresso weight of 18 grams
to
1:2.5, which corresponds to, for example, 9 grams of coffee grounds and an espresso weight of 22.5 grams
Coffee machine inventions like the capsule machine or fully automatic coffee machine have, in the truest sense of the word, watered down what we knew as a classic, strong espresso. These machines brew with different proportionality and accordingly the strength of the drink changes. Nevertheless, both claim to brew "espresso."
This has major implications for the taste expectation of what an espresso is. In the coffee bar, more and more people are giving baristas feedback that their espresso is too strong. This is due to changed habits and taste expectations.
Strength and extraction – the foundation of good brewing
In a detailed video, I've explained the relationships between strength and extraction. Here's the short summary. The proportionality of strength and extraction is the prerequisite for coffee to taste good.
Strength is the concentration of dissolved coffee particles. Each drink has a very typical strength that is characteristic.
We achieve this concentration by extracting coffee. Not everything we can extract from the coffee bean is tasty and desirable. It's a narrow corridor that we want to extract. The target extraction corridor is 18–22%. Lower extraction leads to the sour taste of under-extraction, and higher extraction leads to the bitterness of over-extraction. The golden mean is balanced, sweet, and delicious. When we hit it just right, we call that the sweet spot, where everything is in balance.
The extraction of all coffee drinks aims for the same value while the strength differs. Logical, really, because we want to use only the delicious parts of the coffee bean for all coffee drinks.
To achieve different strengths and thus different coffee drinks, adjusted dosages are used.
Why a coffee spoon doesn't make sense
Unfortunately, it's impossible to fill a spoon the same way every time. A few grams of difference happen quickly and multiply with the number of spoonfuls. If 9 grams instead of 7 grams of coffee per 100 ml are used for filter coffee, this inevitably leads to under-extraction and thus unpleasant acidity in the taste.
Also, coffee weighs different amounts depending on the roast level and origin and has a different volume. A heaped teaspoon of light-roasted coffee is much heavier than a heaped teaspoon of dark-roasted coffee. Dark coffee has more volume but less density.
If you only orient yourself by the heaping of a spoon, inaccurate dosing is pre-programmed.
How large is a classic coffee cup?
A typical coffee cup holds about 150 to 200 milliliters. In gastronomy, such cups are often also used for cappuccino. If a visit is announced and a certain number of cups of coffee should be brewed, I recommend using a calculation of 200 ml as a basis.
So let's brew with the classic brew ratio of 6 grams of coffee to 100 ml of water. 4 cups of coffee should come out, so we brew 800 ml with 48 grams of coffee. Per gram of coffee used, 2 grams of water remain in the coffee cake. We thus get a total of 800 grams minus 2 x 48 g coffee, so about 700 ml of coffee and thus about 175 per cup. Perfect!
The principle that 2 grams of water per gram of coffee used are absorbed in the coffee cake only applies to filter coffee methods without pressure. With espresso and also the Aeropress, other residues remain.
How many grams of coffee for the French Press
When visitors come for coffee, the French Press is also a good option for brewing larger volumes of coffee. The French Press is also called a plunger pot and belongs to the alternative brewing methods. Water and coffee remain in contact throughout the entire brewing process. In technical terms, this is called "full immersion."
I like to brew the plunger pot with 7 grams per 100 ml. Although the coffee is in contact with the coffee for a long period of 3–5 minutes. However, after the first stirring, there is hardly any swirling, so the extraction proceeds more slowly than with classic filter drip methods.
Due to the dosage in the higher range, I still achieve sufficient strength of the coffee drink. At the same time, the extraction is somewhat lower, which leads to a slightly more noticeable acidity.
With the plunger pot, the plunger with its metal screen stops the extraction and separates the coffee grounds and coffee drink from each other. Coffee oils and some sediments remain in the coffee drink – unlike with a paper filter. The coffee oils and sediments cause a less transparent coffee flavor. Due to the lower extraction and the associated acidity, the flavor is balanced. Stronger extraction would intensify the bitterness of the plunger pot.
Conclusion on dosage
The amount of coffee grounds to be used for all drink types is more or less predetermined by the extraction capability of the coffee. This is practical because it provides guidelines to follow.
Anyone who wants to experiment with coffee and try different brewing methods has a huge playground anyway. With our guide, you can first precisely determine the dosage and then concentrate on other factors such as grind size or water temperature.
