If you’ve read more than one cold brew coffee recipe, you probably found yourself confused. The type of coffee, coffee-to-water ratio, and how long to brew it, varies from recipe to recipe.
And you don’t know what you’re going to get until you make it yourself, or how to tweak it for something different.
Well, we’re not coffee experts, but we are researchers.
So we analyzed the 50 most popular cold brew coffee recipes written by food blogs, elite chefs, recipe sites, coffee roasters, and cold brew coffee maker companies (check out the recipe list here).
This scientific approach allowed us to make sense of the patterns and create the ultimate guide to making cold brew coffee, just the way you like it.
Our analysis revealed 4 key variables to making cold brew coffee. Below, we’ve outlined how you can adjust each one to make a cold brew coffee that perfectly suits your taste.
In This Article
- The 4 Cold Brew Variables
- Infographic – Customize Your Cold Brew: Tweak These 4 Variables
- 6 Steps to a Fantastic Cold Brew
- How Much to Dilute Your Cold Brew Concentrate
- Acidity and Caffeine Levels: Hot Brew vs. Cold-Brew
- How Long to Store the Cold Brew Concentrate
- The Best Types of Cold Brew Coffee Makers
- The Top 50 Cold Brew Coffee Recipes We Analyzed
The 4 Cold Brew Coffee Variables
There are 4 main variables influencing how your cold brew coffee ends up tasting. While they also apply to hot brewed coffee, the range is much different when you’re making cold brewed coffee.
- Grind Size
- Coffee Roast
- Coffee-to-Water Ratio
- Brew Time
We’ll explain all of this in detail below, and guide you on how to adjust them for a cold brew customized to your liking.
1. Grind Size
The top 50 cold brew recipes consistently recommended a coarse grind. This is particularly important if you’re using a metal or plastic filter, rather than paper. A coarse grind is less likely to sneak past the filter and leave sediment in your coffee.
Shouldn’t this be more complicated? Doesn’t grind size affect the concentration of caffeine? We’re so glad you asked…
It’s true, the grind (fine, medium or coarse) changes how much caffeine is extracted. But here’s the catch: the quicker the brew, the less time there is for caffeine to be extracted. For quick brews (for example, drip coffee), a fine grind will expose more surface area and allow more caffeine to be extracted, and of course, flavor.
Since making cold brewed coffee takes hours, there is plenty of time to completely extract all the caffeine from a coarse grind (Fuller and Rao).
And yes, it means that cold brew coffee has considerably higher caffeine concentrations than hot brewed coffee. But don’t forget, you’ll ultimately be diluting it because you’re actually making a concentrate. It goes without saying that diluting it will bring down the amount of caffeine in your cup.
Further on in the article, we’ll show you our table comparing the amount of caffeine in cold brews (diluted and undiluted) compared to a cup of hot brewed Starbucks coffee.
2. Coffee Roast
Most of the 50 recipes we analyzed didn’t suggest what roast to use. If they did, they recommended making cold brew coffee using a medium roast. But really, this comes down to personal preference.
Keep in mind that, whether you’re making a hot or cold brew, the darker the roast, the less caffeine and chlorogenic acid it will have (Fuller and Rao).
So if you want less caffeine and less acidity, choose a darker roast. If you want more caffeine and higher acidity, choose a lighter roast. Or, go with Medium, which most Americans prefer.
3. Coffee-to-Water Ratio
Recommended: 1 oz of coffee grinds to 1 cup of water
Making cold brew coffee requires using more coffee grinds than hot brewed coffee. This is because you’re making a concentrate that you later dilute with water.
Adjusting the coffee-to-water ratio will change how weak or strong it tastes. Many people mistakenly believe that “strong” coffee has more caffeine. When coffee tastes strong, it means more coffee grinds have dissolved in the water, not that more caffeine has been extracted. If you want more caffeine in your cup, use a lighter roast.
So what’s the optimal coffee-to-water ratio for cold brew coffee?
When we began looking at cold brew coffee recipes, we found this to be the most confusing variable. But once we analyzed the data, a pattern emerged.
The average recommended ratio was close to 1 oz of ground coffee to 1 Cup of water. However, it ranged from 0.5 oz to 2 oz for each cup of water.
The ratio you use will ultimately come down to personal preference. Depending on how much coffee you’re brewing, and how strong you like it, you’ll have to do some math.
In case you haven’t had your coffee yet, we put together a table that calculates exactly how much coffee and water to add. Simply find the size of your coffee maker and add the specified amount of coffee and water based on whether you like your coffee weak, balanced or strong. We included the amounts in ounces for those who like to make their coffee using precise measurements.
Get the Print-Out
Get this table as a pdf so you can refer to it when making your next cold brew.
4. Brew Time
Recommended: Minimum 8 hours
The main difference between cold brewed coffee and hot brewed coffee is that it uses time, instead of high temperatures, to extract the aromas, flavors, and caffeine from the coffee beans. So while a hot brewed coffee can be prepared in minutes, cold brewed coffee takes hours. If you don’t brew it long enough, it won’t have all the glorious features we expect from a good cup of coffee. If you brew it too long, it will taste bitter.
So exactly how many hours should you let a cold brewed coffee brew?
We analyzed the number of hours recommended by the 50 most popular cold brew recipes. The average recommended brew time was 16 hours. However, the recommendations ranged from 8 hours all the way up to 36 hours.
We wanted more clarity, so we turned to research. We found a study that tested the affect of brewing time on caffeine and chlorogenic acid concentrations (Fuller and Rao). These are the two compounds critical to your enjoyment of coffee. The study found that the caffeine and chlorogenic acid have been fully extracted around 7 hours.
Customize Your Cold Brew: Tweak These 4 Variables
To summarize, the infographic below depicts the range you’re working with for each variable. Adjust each one for a different result. After a few experiments, you’ll have discovered how to make a cold brewed coffee that perfectly suits your taste.
For those of you saying, “just give it to me straight”, below are our recommendations, based on our research and analysis of the top 50 cold brew recipes.
Grind Size: Coarse
Coffee Roast: Medium
Coffee-to-Water Ratio: 1 oz of coffee grinds for each cup of coffee
Brew Time: Minimum 8 hours
Get the Print-Out
Get this guide as a pdf to share or refer to it when making your next cold brew.
Put It All Together: 6 Steps to a Fantastic Cold Brew
Grind your beans and add them to the pitcher
Add cold or room temperature, filtered water
Mix (or shake) to wet all the grinds and place it in your fridge for 8 to 24 hours
Remove the filter or strain (depending on your style of cold brew coffee maker)
Dilute the cold brew concentrate to taste (see recommendations below)
Add ice or heat, and enjoy
How Much To Dilute Your Cold Brew Concentrate
Remember, you’ve just made a cold brew concentrate. This means you’ll be diluting it to finalize the beverage. Typically, people add water. If you’re going for an iced latte, then add milk or cream. But the options are endless… Bailey’s, Kahlua, coconut milk, the list goes on.
How much liquid should you add? Again, this will depend on your personal preference.
Most of the 50 recipes we analyzed recommended equal parts liquid to concentrate. In other words, about 1 Cup of milk or water for each cup of cold brew concentrate. We personally find that makes it a bit weak, and prefer to add 75% water to the concentrate.
Now, the amount of liquid you add to the concentrate will change the caffeine levels and pH (ie., acidity). We explain this below.
Is Cold Brew Less Acidic and Higher in Caffeine Than Hot Brewed?
You might have heard that cold brew coffee is less acidic than hot brewed coffee. You also might have heard that it’s higher in caffeine.
We compared the caffeine and pH levels in cold brewed coffee to a typical hot brewed coffee. Our analysis revealed that cold brewed coffee is indeed less acidic and higher in caffeine, before you dilute it. Once you add equal parts water or milk, it’s still considerably less acidic. But the amount of caffeine is nearly the same.
How Long to Store the Cold Brew Concentrate
The wonderful thing about cold brewed coffee is that it lasts much longer than a pot of hot brewed coffee. This is simply due to the unique chemical reactions involved when you use time, instead of temperature, to brew your coffee.
Hot brewed coffee will become sour or bitter within a few hours, but this is not the case for cold brewed coffee. Cold brewed coffee does not become bitter nearly as quick.
Depending on how well your container seals out air, you can keep your cold brew coffee in your fridge for about two weeks. Some of the recipes we analyzed recommended storing it for just a few days, while others said it would last up to a month.
But we don’t think it’s anything to sweat over. Why?
Well, when we reviewed cold brew coffee makers, we found the most common size was 32 oz. Assuming you add equal parts liquid to each cup of concentrate, one batch would make about 6 cups of coffee. So in other words, you’ll probably finish the batch before the storage time expires.
The Best Types of Cold Brew Coffee Makers
There is huge variety when it comes to cold brew coffee makers. They range in style from a basic pitcher containing a filter, to more elaborate contraptions. You can even cobble one together with things you have in your kitchen: a pitcher, strainer, and some cheesecloth.
This recipe guide applies to any type of cold brew coffee maker. But we recommend keeping it simple. The style we’ve come to call ‘pitcher-and-filter’ is affordable, mess-free and easy-to-use.
In fact, we analyzed over 11,000 reviews of this type of cold brew coffee maker. Based on our analysis, County Line Kitchen’s Cold Brew Coffee Maker is the best option overall. Read our full review to see the 30 best cold brew coffee makers and compare their features.
Once you’ve got your cold brew coffee maker, the fun begins. Follow this simple guide and you’ll be crafting cold brew coffees that perfectly suit your taste.
The Top 50 Cold Brew Recipes We Analyzed
Starbucks Coffee Company. “Beverage Nutrition Information”. https://globalassets.starbucks.com/assets/94fbcc2ab1e24359850fa1870fc988bc.pdf
Fuller, Megan, and Niny Z. Rao. “The Effect of Time, Roasting Temperature, and Grind Size on Caffeine and Chlorogenic Acid Concentrations in Cold Brew Coffee.” Scientific reports7.1 (2017): 17979.
Reddy, Avanija, et al. “The pH of beverages in the United States.” The Journal of the American Dental Association 147.4 (2016): 255-263.