News 31 Jul 2019

What is the perfect coffee ratio? The math behind the perfect cup of coffee

31 Jul 2019
#Coffee brewing #Gina

What is the perfect coffee ratio? The math behind the perfect cup of coffee

So what‘s the deal with this ratio that everyone is talking about? It is actually one of the first “settings” when you are brewing a cup of coffee.

Many times you can hear (read) that while brewing coffee, someone used the ratio 1:15. So what does that actually mean? Simple: for each 1g of coffee, 15g of water is used. If 20g of coffee is used, 300g of water is needed to achieve the 1:15 ratio.

The simplest way to get your coffee-to-water ratio right is by using the GINA app. It connects to an integrated scale in the GINA coffee brewer.


The perfect ratio

Does it exist? Kind of …

There is the term we know as Golden Ratio. 55g of coffee for 1 liter of water. That roughly equates to a ratio of 1:18. This is the ratio that SCA suggests is the base for getting those flavors out of coffee. But as with all things brewing, don’t make it a rule. And from our point of view, the 1:18 ratio is a bit on the light side. We usually brew our coffees with a ratio of 1:15 (also the default ratio in the GINA app). Sometimes we go even lower, just a few days ago we were brewing a washed Brasilian coffee that was terrible at 1:17, better at 1:15 and absolutely lovely at 1:12. But not all coffees can take it … light and delicate Kenyans will love more water for instance.

So how to start? Go with 1:15 and also try 1:17 and 1:13. You’ll taste the difference and find a recipe that suits you (and your coffee).


What happens if …

  • I brew my coffee with a very strong ratio (let’s say 1:7)?

You’ll get a highly concentrated coffee. Too concentrated. But the trick is that you can not simply bypass it (dilute with hot water) as your concentrated brew is also under-extracted. There was simply not enough water pouring through the beans thus the timing was too quick and voila, under-extracted coffee.


  • I brew my coffee with a very weak ratio (let’s say 1:22)?

You will end up with a weak cup of coffee that will be over-extracted. Too much water for a small amount of coffee increases the contact of water to coffee and increases extraction. You will most likely get a tasteless and astringent cup of coffee. The kind that only leaves you with a dry and bitter feeling in your mouth. Not very enjoyable.


The math

Although calculating the coffee to water ratio is a simple task, we still see that some people are struggling with the math. So here it is, coffee ratio 1-2-3.

Okay. I have 1g of coffee and 1g of water. Combine those two and the ratio is 1:1. Makes sense, right? If I have 1 g of coffee and 15g of water, my ratio is 1:15.

But nobody brews 15g of coffee.


Let’s say you’re aiming for a 300g cup of coffee. To keep the ratio at 1:15 you will need:

 300g / 15 = 20g.

20g of coffee + 300g of water for a 1:15 ratio.


Okay, let’s make it the other way around … you have 30g of coffee and want to brew it at 1:15.

30g x 15 = 450g

30g of coffee + 450g of water for a 1:15 ratio.


It’s all very simple math. You’ll just need to calculate manually or use a calculator. Or if you want to have your ratio simplified to the max, you can simply use the GINA Smart Coffee Instrument. The app guides you through the process of brewing coffee and you can simply set the desired ratio. The app will do the math for you.


Don’t forget, there is no one golden rule. Each coffee is different and each coffee drinker is different. Try different ratios with different coffees and find the recipe you like. Easy peasy! And fun, as there is a lot of coffee to be tasted when dialing in your recipe!