The amount of coffee grounds to 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 will learn everything about the correct "dosing amount" and the appropriate brew ratio, the best measuring method, and the universal recipe.
The Dosing Amount is No Coincidence
The amount of coffee used is a prerequisite for a balanced brew. Whether we are brewing 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 coffee grounds, which then create the coffee flavor in the cup.
The less coffee powder we use, the less can be dissolved by the water. The grind size of the coffee also plays an important role in extractability, but we will address that elsewhere.
Little Coffee Powder, A Lot of Water – Over-extraction
If we add a lot of water to a small amount of coffee and extract it for a long time, e.g., in a French Press, the water dissolves a large part of the soluble coffee particles from the coffee. The problem is that not all of these coffee particles are delicious. The longer and more extensive an extraction is, the more bitter a coffee becomes. So-called over-extraction leaves a dry, constricting feeling in the mouth, which is called "astringent" in technical terms.
Due to the large amount of water, the coffee is simultaneously heavily diluted. Bitter, diluted, dry? Everyone knows it. Not tasty at all!
A Lot of Coffee Powder, Little Water – Under-extraction
If we add little water to a large amount of coffee, we have the opposite result. The small amount of water is not sufficient to dissolve the desired amount of coffee particles. We speak of under-extraction. Under-extraction is sour-aggressive. An under-extracted espresso can also have a salty note.
Due to the use of a small amount of water, the final drink also contains little water. Although we have extracted too little from the coffee grounds, it is 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, due to under-extraction, concentrated acidity in the taste.
Both scenarios – too little coffee in proportion and too much coffee in proportion to water – have a common consequence: they are not balanced. Acidity and bitterness are not in balance. Why? Something crucial is missing: sweetness! The inherent sweetness of coffee is crucial for it to taste balanced and delicious.
So let's go in search of sweetness, or as it is so beautifully called, the sweet spot.
Brew Ratio as the Key to the Sweet Spot
Brewing coffee is neither rocket science nor voodoo. However, there are a few rules to observe when preparing coffee. A very important one is the brew ratio, which varies depending on the type of drink.
Brew 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 brew ratio of 1:16.66
Expressed differently, we can also speak of 6 grams of coffee per 100 ml or 60 grams per liter of water. To represent the brew ratio, the amount of water is divided by the amount of coffee used.
60 grams of coffee per liter is not a random example for a brew ratio, but the standard recipe for all filter coffee methods. Whether you brew the classic Melitta filter or a modern Hario V60 filter, the automatic filter coffee machine or even the French Press – with 60 grams/1 liter or 1:16.66 you'll do well.
How Much Coffee Grounds for Filter Coffee?
The dosing amount for filter coffee is not a coincidence, but ultimately a combination of the preferred taste of the majority of people and mathematics. Those who drink filter coffee have a "perception expectation," stemming from habit and taste.
If 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. The rest, by the way, is water, so about 98%.
To brew this strength in a balanced way, a brew ratio of at least 1:20 and a maximum of 1:14 is required. Converted, this corresponds to a coffee amount ratio of between at least 50 grams and a maximum of approx. 72 grams per liter. In the video above, I even speak of a brew ratio of 1:12 as the strongest concentration. But then a bypass is needed to lower 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 dosing amount should be calculated accordingly.
How Much Coffee Grounds for Espresso?
Espresso is a small, strong drink. Under pressure and with temperature, a large amount of coffee particles are dissolved from a small amount of coffee 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 with a strength of at least 7%, a brew ratio of a maximum of 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 amount of water can be manually weighed and added. This is not possible with a classic espresso machine, as it is flushed directly from the brew head over the espresso.
Therefore, with espresso, the volume of the brewed espresso is measured. The term for the ratio of brewed espresso to the amount of coffee used is beverage ratio.
Recommended ratio for a classic espresso:
1:2, which corresponds to, for example, 9 grams of coffee powder and an espresso weight of 18 grams
to
1:2.5, which corresponds to, for example, 9 grams of coffee powder and an espresso weight of 22.5 grams
Coffee machine inventions such as capsule machines or automatic coffee makers have diluted what we knew as classic, strong espresso. With these devices, brewing is done with different ratios, and the strength of the drink changes accordingly. Nevertheless, both claim to brew "espresso."
This has a major impact on the taste expectation of what an espresso is. In coffee bars, more and more people give baristas feedback that their espresso is too strong. This is due to changed habits and taste expectations.
Strength and Extraction – the Foundation of a Good Brew
In a detailed video, I explained the connections between strength and extraction. Here's a quick summary. The proportionality of strength and extraction is a prerequisite for coffee to taste good.
Strength is the concentration of dissolved coffee particles. Every 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 palatable and desirable. There is a narrow corridor that we want to extract. The target corridor for extraction 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 hit precisely, we call this the sweet spot, where everything is in balance.
The extraction of all coffee beverages aims for the same magnitude, while the strength differs. This makes sense, because for all coffee beverages, we only want to use the delicious parts of the coffee bean.
To achieve different strengths and thus different coffee beverages, adapted dosing amounts are used.
Why a Coffee Spoon Makes No Sense
Unfortunately, it is impossible to fill a spoon consistently. A few grams difference can easily occur and multiply with the number of spoons. If 9 grams of coffee are used per 100 ml for filter coffee instead of 7 grams, this inevitably leads to under-extraction and thus an unpleasant acidity in the taste.
Also, coffee weighs differently depending on the roast and origin, and has a different volume. 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 rely on the heaping of a spoon, inaccurate dosing is pre-programmed.
How Big 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 visitors are announced and a certain number of cups of coffee are to be brewed, I recommend calculating on the basis of 200 ml.
So, we brew with the classic brew ratio of 6 grams of coffee per 100 ml of water. If 4 cups of coffee are desired, we brew 800 ml with 48 grams of coffee. For every gram of coffee used, 2 grams of water remain in the coffee grounds. So, we get a total of 800 grams minus 2 x 48 g of coffee, which is about 700 ml of coffee and thus about 175 ml per cup. Perfect!
The principle that 2 grams of water are absorbed per gram of coffee used in the coffee cake only applies to pressureless filter coffee methods. With espresso and Aeropress, other residues remain.
How Many Grams of Coffee for the French Press
When guests come for coffee, the French Press is also a good option for brewing a larger volume of coffee. The French Press is also called a cafetière 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 French Press with 7 grams per 100 ml. Although the coffee is in contact with the coffee for a long period of 3-5 minutes, there is hardly any turbulence after the first stirring, which means that the extraction proceeds more slowly than with classic drip filter methods.
By dosing in the higher range, I still achieve a sufficient strength of the coffee drink. At the same time, the extraction is slightly lower, which leads to a slightly more perceptible acidity.
With the French Press, the plunger with its metal mesh stops the extraction and separates coffee grounds from the coffee beverage. Coffee oils and some sediment remain in the coffee beverage – unlike with a paper filter. The coffee oils and sediment cause a less transparent coffee taste. Due to the lower extraction and the associated acidity, the taste is balanced. Stronger extraction would intensify the bitterness of the French Press.
Conclusion on Dosing Amount
The amount of coffee grounds to be used for all types of beverages is more or less predetermined by the coffee's extraction capacity. This is practical, as it provides guidelines for orientation.
Those who experiment with coffee and want to try different brewing methods already have a huge playground. With our guide, you can first precisely determine the dosing amount and then focus on other factors such as grind size or water temperature.
