What's the Right Coffee Powder to Water Ratio for Brewing? Expert Guide to Pour-Over Coffee Parameters

The coffee-to-water ratio is a crucial parameter in pour-over coffee brewing. Simply put, with a fixed amount of coffee grounds, there exists an optimal water quantity that can perfectly express the coffee's aroma. Therefore, learning to find the correct coffee-to-water ratio is also an important part of learning to brew coffee.

What is the coffee-to-water ratio?

The so-called coffee-to-water ratio refers to the proportion between coffee grounds and total water amount, which directly affects the concentration of coffee. Regardless of the brewing method used, FrontStreet Coffee always determines the coffee-to-water ratio before extraction. For example, FrontStreet Coffee's shops typically use 15 grams of coffee grounds to produce a single serving of pour-over coffee, then use a 1:15 coffee-to-water ratio, meaning approximately 225 milliliters of hot water are poured.

With other parameters remaining unchanged, the more water poured, the lower the coffee concentration and more dispersed the flavor; the less water poured, the higher the concentration and more concentrated and heavy the coffee flavor. Additionally, more water increases the coffee extraction rate, yielding more soluble substances. As the pouring continues, extraction efficiency continuously decreases. The desirable components in the coffee have already been extracted, and what remains will release undesirable bitter substances, making the coffee bitter and astringent. Therefore, we need to find the appropriate coffee-to-water ratio to achieve optimal concentration and extraction rate.

What does the coffee-to-water ratio actually affect in coffee?

FrontStreet Coffee conducted a small experiment, keeping all other brewing parameters fixed while brewing three pour-over coffees with coffee-to-water ratios of 1:10, 1:15, and 1:20 for comparison.

For the coffee beans, FrontStreet Coffee chose medium-light roasted FrontStreet Coffee Kenya Asalia, with a fixed amount of 15g, then extracted it using three different coffee-to-water ratios. The three parameter sets were 1:10, 1:15, and 1:20, meaning the water amounts for the three coffees were 150ml, 225ml, and 300ml respectively. The grind size was 80% pass-through through a #20 sieve (similar to sugar granules), water temperature was 91 degrees Celsius, and the pouring technique was consistent across all three, using a three-stage method.

Measured with a concentration meter, the 1:10 ratio had a concentration of 1.93%, the 1:15 ratio was 1.35%, and the 1:20 ratio was 1.04%. From this, it's clear that when less water is used, the coffee concentration is higher, and when more water is used, the concentration is lower.

However, it's not as simple as using less water if you want stronger coffee or more water if you prefer it milder. Besides concentration, water amount also affects another parameter related to coffee flavor—the coffee extraction rate. After knowing the coffee concentration, we can easily calculate the coffee extraction rate. The 1:10 ratio had an extraction rate of 16.43%, the 1:15 ratio was 18.55%, and the 1:20 ratio was 19.72%.

The more water poured, the higher the coffee extraction rate. However, by examining the increase in extraction rate, we can understand that if we divide the 300ml water into two parts, the first 150ml already achieves a 16.43% extraction rate, while the subsequent 150ml only increases the extraction rate by 3.29%. (This is why the 40-60 brewing method suggests extracting flavor in the first 40% and adjusting concentration in the remaining 60%).

This means that although less water yields higher concentration coffee, the extraction rate is lower, meaning fewer overall coffee substances are extracted. This is why coffee brewed with a 1:10 ratio tastes only strong, acidic, and bitter—excessive concentration can also cause discomfort.

When more water is used, more substances are extracted from the coffee, but as the extraction efficiency significantly decreases with subsequent pouring, the concentration also becomes very weak. Moreover, soluble coffee substances include both the sweet and sour flavors we enjoy and undesirable bitter flavors. With more extracted substances, bitter substances naturally increase. For instance, coffee with a 1:20 ratio tastes weak, lacking distinct coffee flavor, and carries subtle bitterness.

Therefore, the appropriate coffee-to-water ratio aims to find a balance point between concentration and extraction rate, bringing them to their optimal state.

Must pour-over coffee use the universal 1:15 ratio?

You may have seen many recommended pour-over coffee ratios of 1:15, leading to the impression that this ratio is an unchangeable fixed parameter. This is not actually the case. The reason 1:15 is suggested for pour-over coffee-to-water ratios is that it's a relatively safe ratio (difficult to go wrong), as recommended parameters target a broad audience, including many beginners new to pour-over coffee.

Therefore, a very stable parameter is needed, typically emphasizing variables that are easier to control, such as coffee-to-water ratio, water temperature, and pouring method, to reduce variables. Everything serves to accommodate the very difficult-to-control variable of grind size (many beginners' poor coffee brewing results stem from incorrect grind size).

If you've started researching coffee-to-water ratios, it proves you've already surpassed the beginner stage and have a certain understanding of brewing parameters. Then, what were fixed variables for beginners—such as coffee-to-water ratio and water temperature—become adjustable factors to make coffee taste better.

The difference of 5ml water

How much difference is there between pouring 5ml more or less water? Data from concentration meter tests shows only a 0.02% difference, and considering margin of error, the distinction between the two is almost negligible.

FrontStreet Coffee would like to share a story. Once, when FrontStreet Coffee was brewing a FrontStreet Coffee Geisha coffee, the 1:15 coffee-to-water ratio produced concentrated flavors, and we couldn't detect the "money's worth" flavors. The second time, we adjusted the brewing by pouring just 5ml more water than before (totaling 230ml), and this time, it tasted much more comfortable, and the flavor complexity immediately emerged.

FrontStreet Coffee's experience sharing

Finally, FrontStreet Coffee summarizes some experiences about coffee-to-water ratios to share with everyone:

1. 1:15 is not the only coffee-to-water ratio, nor necessarily the most suitable one. For different coffee beans and personal flavor preferences, it could be 1:14, 1:16, etc.

2. The general coffee-to-water ratio range for pour-over coffee is approximately 1:13-1:18. Within this range, everyone can more easily find the flavor profile that suits them.

3. For harder coffee beans, you can appropriately extend the coffee-to-water ratio, such as between 1:16-1:17. Hardness refers to roasted beans, for example, those grown at high altitudes and lightly roasted.

4. Dark roasted coffees generally present rich, mellow flavors that are quite appealing. You can choose between 1:13-1:15 based on your concentration preference.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

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