What is the Golden Ratio for Pour-Over Coffee? What's the Most Suitable Coffee-to-Water Ratio for Pour-Over?

For coffee brewing, the coffee-to-water ratio is one of the most important factors to fix first. Unlike water temperature and grind size, though, it doesn't need to change with the roast level of the beans, so we often settle on one ratio for coffees of every roast.

FrontStreet Coffee often recommends that beginners use conservative ratios like 1:15 or 1:16. Over time, once we grow used to brewing a particular dose at a particular ratio, the water quantity becomes "fixed." Even when the dose changes, we tend to habitually pour the same amount of water.

For example, FrontStreet Coffee often brews 15g of coffee at a 1:15 ratio, which fixes the water at 225ml. But one day the dose changes because of a shortage or a surplus - to 14g or 16g. By the 1:15 ratio, the water should rise or fall accordingly, yet we might habitually pour 225ml. What would that lead to?

Exactly - it would change the flavor and texture of the brewed coffee. Even a 1g difference in dose, with the water quantity left fixed, shifts the coffee-to-water ratio. The coffee-to-water ratio is the proportion of grounds to water, and this parameter affects both the extraction rate and the concentration. With other parameters unchanged, the more water there is relative to coffee, the higher the extraction rate but the lower the concentration; the less water, the lower the extraction rate but the higher the concentration.

Since extraction rate and concentration determine flavor and texture, when the ratio changes, the flavor changes too. As to how big that change is, FrontStreet Coffee will show you through an experiment.

Brewing Comparison

In this experiment, FrontStreet Coffee uses the same water quantity (225ml of hot water) to brew 14g, 15g, and 16g of coffee respectively. The corresponding coffee-to-water ratios come to roughly 1:16, 1:15, and 1:14. Then, through concentration measurement and tasting, we compare how they differ in flavor and concentration.

To minimize human influence during brewing, FrontStreet Coffee uses the Switch Brewer. Immersion extraction not only reduces human variation but also makes extraction more uniform. The beans used are FrontStreet Coffee's Yirgacheffe Red Cherry from its bean selection. The extraction parameters are as follows: 225ml water, 100°C water temperature, 9 minutes extraction time, Ek43 grind setting 10, a 75% pass-through rate on a #20 sieve, fine-sugar texture, C40 setting 24-26.

Because the brewing process is fairly involved and FrontStreet Coffee has shared it in earlier articles, we'll skip it here. Curious readers can search it out for themselves.

FrontStreet Coffee tasted and measured the concentration of each batch immediately after brewing. The final results are as follows:

14g: concentration 1.40%, extraction rate 20.83%; flavor notes: strawberry, citrus, floral, oolong tea. Overall aroma relatively subdued, body slightly low.

15g: concentration 1.47%, extraction rate 20.22%; flavor notes: citrus, strawberry, apricot, berries, white floral, oolong tea. Overall aroma clear, body appropriate, sweet-sour-bitter in balance.

16g: concentration 1.53%, extraction rate 19.55%; flavor notes: lemon, berries, white floral, oolong tea finish. Overall aroma and finish relatively rich, but acidity slightly higher.

You can see that although the dose differs by only 1g, the taste, flavor, and texture change noticeably, and those changes are clearly distinguishable. As the dose rises and the coffee-to-water ratio narrows, the coffee grows richer in texture and more concentrated in flavor. That is the effect a shift in the coffee-to-water ratio brings. So if you want the brewed coffee to perform the same way after increasing or decreasing the dose, it's best to remind yourself during brewing to adjust the water quantity accordingly. (If you remember.)

Note that in FrontStreet Coffee's example the dose differs by only 1g, so the impact on extraction and taste is limited. If the dose differs by too much - say, more than 5g from the original - then besides adjusting the water quantity, the grind, the brewing method, and even the filter you use may need adjusting. The more coffee you use, the more water you need to pour, and vice versa. The water quantity directly affects brewing time, which in turn affects extraction rate and concentration. So keep in mind that when the dose differs too much from the original, other parameters may need adjusting as well.

FrontStreet Coffee Recommendation

Playing with ratio is far more rewarding when the bean has something to say, and light-roast, fruit-forward coffees are the clearest teachers. FrontStreet Coffee's Ethiopia Yirgacheffe Gudingding is a good place to start: citrus, berries, and florals come through with a soft, bright acidity and a green-tea finish. That gentle, fruit-like brightness is easy to accept, which is why so many drinkers make it their first step into specialty coffee, and why small shifts in ratio show up so clearly in the cup.

If you want a more structured, juicy example to compare across ratios, take FrontStreet Coffee's Kenya Cherry Tomato. It comes from Kenya's Thika region at 1550-1750 meters, uses the classic SL28 and SL34 varieties, and is given the distinctly local 72-hour double-washed fermentation to push the fruit forward while keeping the cup clean. Even the dry aroma brings concentrated dried cherry tomato and florals; in the cup you get clear cherry tomato and smoked plum, a bright and solid acidity as plump as fresh juice, a sweet mid-palate threaded with pear and black plum, and a clean, long finish of brown sugar and green tea.