Coffee Ratios and How They Affect Your Brew (with actual test results)

In this article, we will explore one fundamental concept in brewing coffee — brewing ratios. It is one parameter that is usually mentioned when looking at brewing recipes no matter what method you use to make your coffee. 

To find out our “Golden Ratio”, we conducted a little test to experiment on different brew ratios. Read until the end to see our results!

What are coffee ratios? 

Essentially, coffee ratios refer to the amount of coffee grounds relative to the amount of water you’ll use to brew. It is usually presented as:

1 gram of ground coffee : 𝑥 grams of water

For example, when a barista (or coffee enthusiast such as myself) uses a 1:15 ratio for brewing, that implies that 15 grams of water is needed to brew 1 gram of coffee. Most recipes will recommend brewing with ratios between 1 : 15 to 1 : 18. 

When preparing to brew a cup, the ratios can be scaled up depending on the weight of the coffee. Let’s say I want to brew 20 grams of coffee with a 1:15 coffee ratio. This means that my total water weight should reach 300 grams.

Ratios don’t only affect the total volume of your brew. They also control how strong your final cup will taste. Shorter ratios are more concentrated, which will lead to a stronger cup. Conversely, longer ratios will not be as strong. But they will provide more clarity and better distinction across flavors. 

Why coffee ratios matter

Coffee ratios are one aspect of how flavors get extracted. They are crucial for brewing a good cup of coffee consistently. You’ll need to keep a scale handy for this.

The amount of water used while brewing will affect the resulting brew. Too much water will result in a weak brew that can be quite bitter as the water will bring out more of the bitter flavors. Too little water will result in an overly acidic and sour cup as water can only hold a limited amount of dissolved coffee flavors. 

When the brew reaches its maximum concentration, it may stop extracting the later parts of the brew that mellows out the acidic and sour flavors. Therefore, a good understanding of coffee ratios will allow brewers to extract the best bits out of their coffee. 

Why you should use a scale when brewing

Measuring by weight (grams) is more accurate than measuring by volume (cups, scoops) as not all beans are created equal. Some beans are more dense than others because of factors such as the variety of the bean or the roast level. 

That means if I were to grab a scoop of large sized beans and a scoop of smaller sized beans, the latter would give me more coffee. This is due to the empty spaces that are found in the volumetric measurement. 

In this scenario, the bigger beans contain more empty spaces than the smaller beans. Weight measurements measure how heavy an object is and does not take empty spaces as part of its measurement.

Read more: Best coffee scales that won’t break the bank

A helpful coffee ratio chart

Serving size	1 : 14 ratio dose (in grams)	1 : 15 ratio dose (in grams)	1 : 16 ratio dose (in grams)	1 : 17 ratio dose (in grams)	Total brew amount (in ml)
1 cup	14	13	12.5	11.5	200
2 cups	25	23	22	20.5	350
3 cups	36	33	31	29	500

What to consider when choosing a brewing ratio

Brewing method

Different brewing methods require different brew ratios. For example, a cup of drip coffee would need more brew water compared to espresso because they use different forms of extraction. 

They are likewise served in smaller cups and are much more concentrated. 

Brew ratios for immersion brewing methods such as the French Press and Aeropress are also slightly different to that of drip / pour over coffee. The coffee grounds are submerged in the brew water and left there to brew. The concentration increases over time. With immersion brews, the recommended ratio is usually between 1 : 13 to 1 : 15. 

With pour over methods (such as the V60 or Chemex), brew water passes through a “bed” of grounds and what comes out is water mixed with the extracted flavour compounds. Unlike immersion brew methods, the concentration decreases over time. 

Put simply, if you plan to brew with an immersion or filter brew, make sure to take the brew ratio into account to have the most optimal extraction possible.

Coffee origin

Typically, coffees from a particular country will have similar flavour characteristics. For example, Ethiopian coffees are renowned for their floral and fruity notes while Brazilian coffees are quite nutty and bittersweet. For floral and fruity coffees, a longer brew ratio would be optimal in order to balance out the acidity and add more sweetness to the cup. 

Coffees with dominating chocolate and nut notes would benefit from a shorter brew ratio in order to prevent over extraction. Based on my experience, using a shorter smaller ratio for bright, high acidity coffees resulted in a brew that was a little bit too sour for my taste while a larger ratio for chocolatey coffees resulted in a bitter brew.

Roast level

While brewers need to consider their brew ratio based on brewing method and coffee origin, it is also important to know the roast level of the beans prior to roasting. Just like fruity African coffees, lighter roasts generally have more acidity. Thus, more brew water (longer brew ratio) is needed to balance out the acidic flavours to produce a mellower cup. 

Darker roasts are the opposite. They carry a lower acidity and more bitterness because of how they are roasted. As such, they do not contain as many flavour compounds as light roasts. Thus, less water (shorter brew ratio) is needed to hit the sweet spot in terms of flavour.

Age of the coffee

As coffee ages, it releases carbon dioxide and other volatile compounds that contribute to flavour. This is the primary reason why the same recipe would taste different when brewing a few days later. 

In this case, older coffees benefit from a shorter brew ratio so you can extract what’s left of the desirable flavour compounds. On the flip side, fresh coffees will have a lot of desirable flavor you’d want to extract and you’d want to maximize that by extending your brew ratio.

Ratios test

Me and a couple of friends wanted to find out what was the best brew ratio to start out with. Different brews were prepared using four consecutive brew ratios, starting with 1 : 14 and ending with 1 : 17. 

Personally, I also wanted to taste the differences between the four brews and note down my observations to share with everyone.

Parameters

For this test, four Hario V60 brewers and a medium roast coffee from Colombia. A medium roast was chosen since I think it would be representative of most coffees bought from most specialty coffee shops.  

The grind size for the brew was medium-fine (similar to the grind size recommended by Hario). The coffees were brewed with a brew ratio starting from 1:14 to 1:17. After all brews are completed, they are then tasted and comments are noted down.

Test 1: Pour over

Ratio	Total brew time (minutes to seconds)	Results
1 : 14	2:05	Sharp acidity
1 : 15	2:05	Good acidity and sweetness but flavor dies quickly
1 : 16	2:15	Mellow acidity and lingering sweetness
1 : 17	2:20	Mild acidity and bitter aftertaste (only noticeable when coffee cools down)

We also did an espresso test. These are our results: 

Test 2: Espresso

Ratio	Results
1 : 1.5	Sharp acidity, very concentrated
1 : 2	Decent but concentrated flavor; good for mixing with milk
1 : 2.5	Best in taste as standalone espresso; not viscous enough to mix with milk

Recommendations

After tasting all brews, the 1:16 ratio produced the best tasting brew most likely because it extracted the most sweetness from the coffee. Take note that the beans were around a week old when this test was conducted. 

When brewing your own coffee, check the roast date of the beans. If the beans are a few weeks old, then I’d recommend going for shorter ratios (1 : 15 and below depending on how old the beans are).

As for the espresso test, the 1:2 brew ratio was optimal for mixing with milk but was too strong to consume as an espresso beverage. The 1:2.5 brew tasted good by itself but would be too weak to mix with milk and other flavourings. 

Frequently asked questions

Is there a “Golden Ratio” for brewing?

Most recipes will recommend a 1:17 ratio as a starting point, but in testing, a 1:16 brew ratio should give brewers good insight to the flavour characteristics of the coffee. For espresso, a ratio of 1:2 – 1:2.5 should be a good starting point. 

When should I adjust my ratio instead of grind size?

I would usually change my grind size when there’s still too much water left in the slurry after 2’30’’ – 3’00’’ of total brewing time (using the “Golden Ratio”), same goes for water draining too fast. Once I have my ideal grind size, I then move on to adjusting the brew ratio.

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