Making cold brew coffee is generally very easy and straightforward, but there’s one part of the process that easily trips up people: ratios. The confusion comes in two parts:
- The coffee to water ratio when you brew the coffee
- The concentrate to water ratio when you dilute the coffee to drink it
We all know what it’s like to guess at how much water you need to make your cold brew concentrate taste balanced and pleasant.
Pour a little water. Taste. A little more. Taste. More water. Taste. Blast—too watered down.
This back-and-forth is irritating and can throw off your refreshing cold brew experience. Thankfully, there’s a way to eliminate this struggle once and for all. I’ll show you exactly how you can brew and dilute your cold brew for perfect balance, strength, and flavor every time.
It All Begins With The Golden Ratios
When it comes to coffee with a balanced flavor and approachable strength, there actually is a range of coffee to water ratios that’s considered objectively better. In this range, the acids are crisp but rounded out by mild lower notes, the sugars are present and sweet, and the aftertaste encompasses all the flavors of the brew.
This is the “sweet spot” we’re always after when making coffee.
Now let me show you the actual Golden Ratios: 1:15 to 1:18 (coffee to water).
In here is where most people find the coffee to be at that sweet spot, though there are a few exceptions, like with espresso, for example.
Here’s why this matters.
Even though cold brewing is fundamentally different than regular hot brewing, these golden ratios are still appropriate for the tastes of most people. So the end goal is that your final glass of iced coffee falls within these golden ratios.
Let’s see how you can get there for better, more consistent, and more balanced iced coffee.
Stick With A Specific Brewing Ratio
Making cold brew coffee usually results in a coffee concentrate. The typical recipe has you make extra-strong cold brew that you dilute with water.
For this to work, you’re going to want to find a brewing ratio you like and stick with it.
For example, in our JavaPresse Ultimate Guide, we use a 1:7 brewing ratio with 100g of coffee and 700g of water. This means our final cold brew concentrate is going to be a little more than x2 as strong as your typical hot coffee (1:7 vs 1:15, for example).
Of course, you can really brew to any strength as long as you stick to it for consistency’s sake. 1:5? No problem. 1:3? Go ahead!
Now here’s the important part: you need to know how strong your concentrate is relative to your goal. Like I said, our 1:7 ratio is just slightly over x2 as concentrated as the goal. But a 1:5 ratio—that’s nearly x3 as strong.
If you need to, write this number down—you’re going to need it when it’s time to dilute.
Dilute Just Enough To Reach A Golden Ratio
Okay, so if the goal is for your final glass of iced coffee to fall within the Golden Ratios, then you’re going to need to dilute your concentrate with water to that point.
Now that you know your brewing ratio, it’s going to be pretty easy.
So, with our JavaPresse guide, our final concentrate ends up about a 1:7 ratio. To bring it up to 1:15, for example, we need to dilute the concentrate with an equal amount of water to reach a 1:14 ratio.
At this point, we can either add some extra water for reach 1:15 or 1:16, or we can just add ice and let that help water the iced coffee down over the next few minutes. Success! We now have rich and balanced iced coffee.
So what if you have a stronger cold brew concentrate brewed at a 1:5 ratio? Cut the concentrate with twice the amount of water to reach 1:15. Now just add some ice and enjoy!
And what about a super strong 1:3 ratio? Dilute with five times the amount of water for 1:15
See how this works? It’s just easy math!
There are a few ways you can dilute, but not all of them are equal in effectiveness.
- Eyeball It — Pouring by eye can work, but it’s pretty difficult to do consistently unless you have a really straightforward dilution method (like using an equal amount of water).
- Measuring Cup — A liquid measuring cup is a simple way to make sure you’re actually reaching the proper ratio. For example, if you need to cut 150ml of concentrate with an equal amount of water, you just fill to 300ml. Easy!
- Coffee Scale — A scale basically works the same way as a measuring cup. Add 150g of concentrate, mix with 150g of water and you’re finished.
A measuring cup is probably the easiest and quickest way to accomplish this, but a scale’s just as accurate. If possible, avoid eyeballing it since it’s by far the least accurate or consistent method.
Making excellent cold brew coffee is really just about finding that strength and flavor sweet spot—just like with any other kind of coffee. Once you know how to dilute your concentrate according to the brew ratio, you’ll never have to worry about overly strong or too watered down iced coffee again.
That being said, if you’re starting off with low-grade or stale beans, the golden ratios may not be able to work their magic. Freshly roasted, high-quality beans are the true key to unlocking incredible and balanced flavors. Sadly, it’s so easy to go cheap on the beans and not realize what we’re missing out on.
Subscribers to our JavaPresse Coffee Club, however, can recall what it was like to cold brew with low-grade, stale coffee beans—and they’re not going back!
We source beans from some of the best small-batch and family-owned farms in the world. We then roast those beans in a way that pulls out the best flavors and ship them to you the same day so you know you’re getting uber-fresh coffee when they arrive in the mail.Don’t settle for disappointing cold brew—check out the Coffee Club for yourself!