Cold Brew Coffee Ratios Demystified
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Look around for a simple answer to how much coffee and water to use in your home cold brew and you’ll get a lot of answers. Most of them are expressed in ratios. You were hoping there would be no math involved (good news, there doesn’t have to be).
Feel free to click on the links above to skip to the section you want. Once you understand what the ratios mean, go ahead an give my cold brew ratio calculator below a try.
Interpreting cold brew ratios (what do they really mean by 1:3??)
You may see different ratios for coffee ranging from 1:3 all the way up to 1:18.
The ideal ratio for hot coffee is between 1:15 and 1:18.
For cold brew, it ranges from 1:3 to 1:6.
What they don’t always tell you is that this is by weight.
So, a 1:5 ratio would be for every 1 g of coffee you would use 5 g of water.
Fortunately, 1 gram of water is the equivalent of 1 ml of water.
Let’s say you want to make 1 cup (8 oz.) of cold brew, ready to drink using a 1:5 ratio.
1 cup of water is technically 237 ml. Sometimes people use 250 ml because its just easier mental math. I don’t worry about 13 ml more or less (it’s less than a tablespoon difference).
So let’s go with 250 ml. To get the amount of coffee I need with a 1:5 ratio I need to divide this by 5.
250/5=50 grams of coffee.
Here is a handy table of common cold brew ratios.
| Water Amount | Ratio | Coffee (g) | Strength |
|---|---|---|---|
| 500 ml | 1:6 | 83 grams | Ready to drink |
| 500 ml | 1:5 | 100 grams | Strong ready to drink |
| 500 ml | 1:4 | 125 grams | Weak concentrate |
| 500 ml | 1:3 | 167 grams | Concentrate |
| Water Amount | Ratio | Coffee (oz) | Strength |
|---|---|---|---|
| 2 c. (16 oz.) | 1:6 | 3 oz. | Ready to drink |
| 2 c. | 1:5 | 3.5 oz. | Strong ready to drink |
| 2 c. | 1:4 | 4.4 oz. | Weak concentrate |
| 2 c. | 1:3 | 5.9 oz. | Concentrate |
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How cold brew ratios translate to more useful measures like cups or tablespoons
The most accurate way to dose your homemade cold brew is by measuring out coffee and water by weight. But what if you don’t have a kitchen scale?
The water part is easy, water weight doesn’t vary much so just translate grams to milliliters.
1 g water = 1 ml water
The weight of coffee can vary depending on where it is from, the varietal, processing, and the degree of roasting (Source). A lot of this comes down to moisture loss from the bean. After all, we all weigh more soaking wet than when dry so coffee beans are not much different in that respect.
Another factor to consider when you can’t weigh your coffee is how much coffee you can fit into a tablespoon will vary depending on whether it is coarsely ground or finely ground. We can fit more sand in a jar than pebbles.
To account for differences in weight, I err on the side of making my cold brew too strong. My mantra around here is:
You can always dilute cold brew that is too strong, but cold brew that is too weak is useless.
As a test, I weighed 1 T. of coffee that I ground medium-coarse and then I also took pre-ground store bought coffee and weighed that. Use this table as a general guideline. I used an actual tablespoon measure, not a coffee scoop so that results are standardized (coffee scoops can vary in size).
| Coffee | Grind Size | Weight |
|---|---|---|
| Starbucks Decaf Medium Roast | Preground (looks medium-fine) | 5 g |
| Hollis St. Colombia Medium Roast Whole Bean | Medium Coarse | 4 g |
So, now we can do some math to come up with some approximate ratios using kitchen measurements. As I researched this post, I determined the consensus is that 1 T. is usually roughly 5 g. That’s easier math so we will use that in the following table:
| Water | Ratio | Tablespoons | Cups |
|---|---|---|---|
| 500 ml (about 2 c.) | 1:6 | 17 T. | 1 c. |
| 500 ml | 1:5 | 20 T. | 1 1/4 c. |
| 500 ml | 1:4 | 25 T. | 1 1/2 c. |
| 500 ml | 1:3 | 33 T. | 2 c. |
So yes, thats a heck of a lot of coffee.
What is the best ratio for ready to drink cold brew vs. the best ratio for a concentrate?
If you would like to brew a coffee that is drinkable as is, use the 1:5 or 1:6 ratio. If you want to make a concentrate, use 1:3 or 1:4.
An easy cold brew ratio: just eyeball it
After years of trial and error, here is how I eyeball my amounts without weighing. Somewhere, someone in Seattle just got a shiver down their spine at my lack of precision, but what matters is that it tastes good.
I pull out a mason jar, any size but I typically use the quart size. I fill it 1/3 full of coffee grounds, and then fill it up with water.
The result is stronger than Starbucks, but just needs a splash of water to dilute it to a nice strong smooth cup. Easy peasy. No math. No measuring.
My FIL had a saying, toast it black and scrape it any shade you like it. For cold brew, make it strong and dilute it to taste.
