Coffee Experts Determined the Perfect Brewing Balance, and It’s Called the ‘Golden Ratio’

Wondering why your daily coffee doesn’t taste as good as the one your barista makes? You’d think that after a lifetime of drinking the stuff you’d have developed some sort of instinct, but “looking at it” is the reason. These habits are the only thing that separates you from a cup that actually tastes like it came from a coffee shop.

If you want a guaranteed win every morning, you need to embrace the “golden ratio.” It’s not just a pretentious barista term; it’s the literal industry standard for the balance of coffee and water that ensures perfect extraction. By letting go of the guesswork and using a consistent formula, you stop the cycle of bitter, overextracted pots and watery disappointments. It’s the easiest way to turn a random cooking routine into something truly reliable.

There is some flexibility with the ratio since some people like their coffee stronger – or weaker – but starting from this ratio is wise for anyone still playing the coffee guessing game.

To learn more about the rented ratio and other variables that influence coffee brewing, I spoke with Kaleena Teoh, director of education at Coffee Project New York. Teoh’s advice applies to those who use a filter coffee makerFrench press or pour-over system, learning the basics of balance will help you get better coffee.

(Editor’s note: If you use K-cups or other pod coffee system, the ratio is controlled by the machine, so this lesson does not apply. And those who prepare espresso have a slightly different set of brewing standards to consider.)

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What is the golden ratio?

The golden ratio refers to the ideal proportions of water and ground coffee at the start of the brewing process, resulting in a full, balanced cup.

“The Specialty Coffee Association, an international organization that largely governs the guidelines we use, suggests between a Ratio of 15:1 to 20:1” said Teoh. “It literally refers to the amount of water versus the amount of coffee grounds. And then the volume you get at the end can vary entirely depending on what type of system it is (whether it’s an automatic drip, French press, or pour-over).”

The golden ratio is based on weight, not volume

It should be noted that this ratio is based on weight and not volume. Although teaspoons can be calibrated to a particular grind for a specific type of machine, the effectiveness of the ratio relies on a more precise measurement. A tablespoon can hold a different weight of coffee, whether it’s fine espresso powder, conventional pre-ground coffee, or coarse cold brew grounds.

The goal of this precise ratio is flavor, with the appropriate strength to taste real coffee without high acidity, which reveals under-extraction, or astringency, which reveals over-extraction, and which can withstand additions like milk or sugar.

“Personally, I use a ratio of 16 to 1,” Teoh said, “which is often touted as the ideal in the 15 to 20 range. I think that’s fine, not too strong, and that’s a good place to start.”

This ratio would ensure that you taste the coffee even if you add elements.

The higher the ratio number representing water, the milder (or weaker) the resulting brew. So if you’re having your coffee black, you might consider a slightly different ratio, like 18 to 1. If you’re drinking it light and sweet, you might try a 15 to 1 ratio for stronger coffee.

Other factors influence the effectiveness of the ratio

The ratio alone is not enough to guarantee an optimal cup. The following elements also play an important role in the outcome of the brewed coffee.

Grind size

The grind size plays a vital role in how the coffee is extracted. Conventional pre-ground coffee usually has a ‘medium’ grind suitable for most filter coffee machines, but this is not always suitable for all methods. According to Teoh, a French press generally requires a coarser grind, “like sea salt,” while pour-over can benefit from a slightly finer grind than can be found on supermarket shelves.

Temperature

Temperature also impacts how the coffee is extracted. “As soon as the water comes into contact with the coffee, it starts to extract, whether it’s cold or hot,” Teoh said.

Cold brew is, of course, a magical thing, but when it comes to hot coffee, there’s an ideal temperature range and—news flash—it doesn’t boil.

The SCA suggests temperatures between 195 and 205 degrees Fahrenheit, or temperatures that allow extraction to maximize certain flavor compounds in coffee, while still maintaining an appropriate temperature for drinking, she said.

Hustle

Agitation refers to the movement of the grounds during extraction. “The more you shake it when extracting coffee, the more concentration occurs during brewing,” Teoh said. Agitation is limited in standard machines for brewed coffee, but plays a role in French press and pour-over methods.

Let’s say you’ve experimented with various filter coffee machines and coffee grounds and have always been a little disappointed with the results. In that case, it might be time to consider getting nerdy with something like pour-over, which can be difficult, but can help with this aspect of the brewing process.

Filtered

The filter you use is the last barrier between what happens during the extraction process and what ends up in your cup.

“Different filters have different sized pores, allowing or not allowing certain elements to pass through,” Teoh said. “Metal filters will remove all of the solubles and some of the insolubles, while a paper filter will be able to trap all of those insolubles, giving you a very clean cup.”

Insolubles can refer to tiny granules of ground coffee and the natural oils found in coffee.

One is not necessarily better than the other; it’s a matter of preference. Oil can add body to coffee, but that’s not necessarily always desirable for everyone, either visually or textually, she said.

Best Practices from a Coffee Expert

To get the most out of the golden ratio, Teoh suggests practices that can make a noticeable difference in your daily brew.

Measures

The golden ratio depends on weight, so a scale is recommended to achieve this ideal balance of 16 to 1 water and coffee grounds.

“Everything is weighed in most coffee shops to ensure consistency,” Teoh said, noting that this applies to grounds, water and, in the case of espresso, the resulting brew.

If you’re serious about improving your coffee intake, a scale is an essential investment, and it doesn’t have to be expensive.

Aside from that, “any unit of measurement that makes sense to the brewer, to have some sort of consistency throughout day-to-day brewing, is better than nothing,” Teoh said.

That’s bad news for the “eyeball it” method, but good news for those for whom a kitchen scale is just one gadget too many, she said. However, if you want to measure by volume, whether with a tablespoon or teaspoon, Teoh advises experimentation and precision to determine the best result for you.

Coffee quality

Of course, a better cup of coffee also starts with better coffee, regardless of the measurement system.

“Fresh beans will always taste better,” Teoh said, advising caution when getting freshly roasted coffee.

Look at tasting notes, talk to roastery staff and taste different blends to determine whether you like something bright and acidic, like with a lightly roasted coffee, or more floral and fruity notes, like with a darker roast, she said.

Crusher

More than the scale, and even more than the coffee maker itself, Teoh recommends a device that can really affect the quality of your coffee.

“The best investment is actually the grinder,” she said. “Get a coffee machine that can do its job. It doesn’t have to be the most expensive. But a burr grinder is actually a great investment.”

Ideally, as with a cheaper model, you want a grinder with settings that take the guesswork out of determining the fineness of the grind.

“If you just buy pre-ground coffee and grind it fresh, you’ll see a big difference in the cup,” Teoh said.

Consistency

Finally, the most crucial factor combined with all of the above is consistency and not committing to products or processes that you cannot follow regularly.

“Just use a method that works for you and that you can use every day, because if it’s too much and too complicated, you’ll eventually stop,” she said.

“Choose something you’re comfortable with and can do consistently,” whether with a particular ratio, particular beans or particular appliances, Teoh said. “And then play with it. Experiment until you find something you like.”