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Coffee Brewing Ratios Explained

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Ahh yes, the golden coffee ratio. The perfect balance between coffee and water for brewing a consistent cup of coffee each and every time. Many coffee brewing beginners tend to struggle with the aspect of brewing ratios, and I often hear that this is one of the biggest barriers faced for those venturing into brewing great coffee at home.

​I can totally understand that transitioning from push-button automatic coffee brewers where almost all stages of coffee brewing are handled by a machine, over to manual pour-over coffee brewing where you have to call the shots can seem daunting. However, if you can nail coffee ratios you’re on your way to churning out some of the best-tasting coffee you’ve ever brewed at home and the days of using those push-button Keurig machines are long gone!

​For any aspiring home barista, it’s critically important to develop the habit of accurate measurement. To do that you’ll need to get your hands on a good coffee scale, there’s really no other substitute for a scale that can measure in grams. With it, you’ll be able to measure your coffee and water which means perfecting your coffee brewing ratios then becomes super easy. Trust me you don’t want to try and guess the perfect coffee and water combination, especially when you just getting your feet wet and learning the basics.

coffee brewing ratio chart

​No Perfect Brewing Ratio: Nothing Is Set In Stone

When you start to research brewing ratios and start to understand coffee chemistry, you will often read or hear that the best relation between the two amounts is somewhere between 1:15 and 1:18. However, this formula isn’t always “set in stone” (if only it were that easy!). Sure a coffee to water ratio somewhere between 1:15 and 1:18 is most probably going to yield great results in most coffee brewers, those ratios are not mandatory and are definitely flexible depending on your personal preference and taste.

  • A brewing ratio of 1:30 (20g of coffee, 600g of water) is going to yield a weak, over-extracted cup.
  • A brewing ratio of 1:5 (20g of coffee, 100g of water) is going to be overly concentrated, but also under-extracted.

​So finding the sweet spot is the key to a great-tasting cup of coffee, and most coffee aficionados believe 1:15 to 1:18 is that perfect ratio range.

​When talking about good brewing ratios, I am referring to what is typically recommended for the most acceptable cup of coffee and often found in manuals supplied with coffee makers of various kinds; this is the “safe zone” that most palates are accustomed to (think Starbucks).

coffee beans on a weighing scale

Coffee Water Ratio

​It’s not as complicated as you think, trust me! Let me break it down into the basics. If you have 1g of coffee and 1g of water your coffee to water ratio is 1:1, are you with me so far? So if you have 1g of coffee and 20g of water your ratio is going to be 1:20, still with me?

​If 1g of coffee and 20g of water gives you a brewing ratio of 1:20, how many grams of coffee do you need if you want to use 200g of water?

The easiest way to tackle this is to start with what you know: 200g of water. Now divide the water mass by the water’s portion of the ratio to then get the coffee mass.

​200 / 20 = 10

​So with 10g of coffee and 200g of water, you now have a ratio of 1:20 and a great-tasting cup of coffee.

​What if you have 40g of coffee and you want to use it all in one brew, how much water are you going to need to ensure you have a good tasting cup of coffee? This is still pretty easy to work out once you have mastered the simple formula, however, this time we are going to multiply your brewing ratio (1:20) instead of dividing.

​40 x 20 = 800

​Since a cup of coffee is 99% water, the larger number in the ratio is typically always going to be water. A lot of coffee drinkers will say 15:1 or 1:15 without clarifying which is which, and this can be confusing at first, especially when you are just starting out.

​Changing Brewing Ratios

And you thought you had mastered it, well not entirely. What if you want to try a 1:15 coffee to water ratio instead but still want to use the same 200g of water. Don’t fret that’s easy peasy, just divide the total water weight by the water’s portion of the ratio, like this.

​200 / 15 = 13.3

​I hope that you have a better understanding of how to work out your coffee brewing ratios. With that said I’m sure most of you reading this are still scratching your head, but once you’ve had time to play around with various ratios you’ll get it in no time. As long as you’ve got a coffee scale and a calculator handy (use your smartphone app) you should have no problems working out the coffee ratio for your next brew.

Adjust the below chart for extra guidance when making your next brew!

Mark Morphew

Mark is a coffee addict. Also, he's the guy behind the coffee blog Bean Ground. You'll almost always find him in a caffeine-induced rant talking about everything to do with coffee! Mark has been active in the catering and hospitality industry for many years and is a proud member of the Speciality Coffee Association. Discover more about Mark here.

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