Coffee brewing ratios are some of the least-understood, but most empowering tools a coffee brewer can take advantage of. I understand being intimidated by weird numbers I don’t understand, so I wrote this guide to be as approachable and simple as possible so that you can implement some simple steps to take your coffee brewing to the next level.

brewing ratios

Just like all variables, ratios are about manipulating strength and yield to achieve the greatest cup possible. A jar of water poured on top of a single coffee bean is not going to make a very strong cup of coffee. That same amount of water poured over 60 beans will be relatively balanced. A jar of water poured over in a tub full of coffee beans probably won’t even yield any brewed coffee, because all the beans will soak up the water.

No Golden Ratio

You will most often hear that the best ratios of coffee beans to water is somewhere between 1:15 and 1:18, but this is not always the case. The US Brewers Cup of 2014 was won with a man using 1:13. While 1:15 through 1:18 may be the most preferred option by most coffee brewers, those ratios are not law. When we talk about good ratios, we are talking in terms of what is generally accepted as preferable.

A ratio such as 1:30 (20g of coffee, 600g of water) is going to yield a weak, overextracted cup. A ratio of 1:5 (20g of coffee, 100g of water) is going to be overly concentrated, but also way underextracted. There is a balanced in-between, and most coffee drinkers believe 1:15 to 1:18 is that range.

Coffee:Water

Understanding a ratio is simple. If you have 1g of coffee and 1g of water, the ratio of coffee to water is 1:1. If you have 1g of coffee and 15g of water, the ratio is 1:15. Nobody brews a 15g cup of coffee. What is more common is a 300g cup of coffee. In order to stay in the generally accepted range of ratios (we’ll use 1:15 for this guide), we need to do some very simple math.

If 1g of coffee and 15g of water is a 1:15 ratio, how many grams of coffee do we need if we want to use 300g of water? Start with what you know: 300g of water. Now divide the water mass by the water’s portion of the ratio to get the coffee mass.

300 / 15 = 20

With 20g of coffee and 300g of water, you now have a 1:15 ratio and a full cup of coffee!

Now imagine you have 30g of coffee left and you want to use it all in one batch – how much water do you need to use to stay in the generally accepted range? Instead of dividing, it’s time to multiply by your selected ratio (1:15).

30 x 15 = 450

Finding the correct ratio for your brewing needs is amazingly simple, and knowing these simple steps will make you look like a coffee guru in front of your friends.

coffee beans

Changing Ratios

What if you think you’d rather try a 1:17 ratio instead of 1:15, but still use that same 300g of water for your usual mug of coffee? Not hard at all! Like earlier, divide the total water weight by the water’s portion of the ratio.

300 / 17 = 17.6

See how easy that is? No sweat. With this tidbit of knowledge and a phone calculator, you’ll be on your way to coffee brewing like never before. Just make sure you have a reliable way of measuring the mass of your coffee and water.

Good luck and happy brewing!

Brewing Ratios for Dummies