We sat down with Joshua del Sol, Director of Coffee, to get the scoop on water-to-coffee ratios and how to use simple math to make a great cup each morning. Here's the wisdom he had to share.
Q: OK, what's the deal with making coffee? We all know coffee beans and hot water make great coffee, but is there some sort of special math to it?
J: Yes, there’s math but it’s not scary, it’s simple. It’s just two numbers: 17 and 1.
Q: 17 parts water to one part coffee?
J: Exactly. Whatever you’re using to measure, it’s just 17 parts of water for 1 part of coffee. So 17 grams of water to 1 gram of coffee.
Q: Now you’re going to tell us we need a scale?
J: Ideally, but you don’t have to. You can measure (scoops, tbsp) instead of weighing, but it’s actually a tougher route. Using a scale is way simpler than you’d think. You don’t ever have to measure or scoop (or lose track of scoops) again.
Q: Okay, so how does a regular person remember this ratio? Got any fun tricks?
J: 1 TBSP of ground coffee is 7 grams. It’s really all simple math from there. But the easiest rule of thumb is that a half cup of ground coffee is about right for a 1L French press or a 12 cup brewer.
Q: Are we essentially talking about the golden ratio?
J: Somewhat. This is the accessible version. The golden ratio, to use ridiculous terms, is the range of flavour acceptability in coffee. All the coffee nerds agree that coffee made using this exact ratio is acceptable.
Q: What’s the official golden ratio?
J: 17.42:1 is the true mathematical golden ratio. But rounding is your friend. That’s why we say 17:1
Q: Does the golden ratio ever change? What about location, or brew method?
J: The only thing that changes is the temp water boils at based on altitude. The golden ratio never, ever changes.
Q: Is there anything else you want us to know about the water-to-coffee ratios?
J: The most fluid part of your coffee experience. It’s a great place to start. Add more water if you want it less strong. Or use less water to make it stronger.
Knowing this ratio is the most powerful way to up your coffee game. Before upgrading your brewer or changing your coffee, try playing with the ratio of coffee to water. It’s the most powerful variable to use.
Method |
Water |
Coffee |
Ratio |
Drip Brewer |
1.2L (1200g / 12 cup maker) |
65g |
18.5:1 |
French Press |
1L (1000g) |
55g |
18.2:1 |
Chemex |
600mL (600g) |
35g |
17.15:1 |
Aeropress |
200mL (200g) |
12g |
16.7:1 |
Here’s a great starting point for brewing. A few methods displaying how the golden ratio looks. Every brew method is a little different – this chart can be a great starting point and you can adjust from here. Happy caffeinating!