As a young student of the culinary arts, there were a handful of “commandments”—central tenets of good cooking—that each of my mentors persistently reinforced (read: screamed). One such precept, which has been indelibly seared into my cortex, is that heat equals flavor. Heat browns meat, caramelizes sugar, and extracts body-giving gelatin from bones. Heat also creates aroma, concentrates flavor compounds, and melts unctuous fats. If heat is so great (which it is), why on Earth am I promoting the practice of combining ground coffee with room-temperature water and letting it infuse slowly for hours? The answer lies in the fact that heat is indiscriminate.
It’s true that coffee brewed at 210 degrees will contain more aroma compounds, dissolved solids, and flavor than coffee brewed at 72 degrees. But this is one case where more isn’t necessarily better. Along with the good stuff, heat also extracts the majority of bitterness and astringency found in hot-brewed coffee. Exposed to far less heat, cold-brew is significantly less acerbic than its sweltering sibling. Less bitterness means that the subtler flavors found in coffee beans are more perceptible. For me, good cold-brew balances hints of dark chocolate, caramel, ripe black fruits, and vanilla with a pleasant viscosity, mild acidity, and pitch perfect bitterness. If my description sounds florid to you, it’s probably because you didn’t have cold-brew this morning. In all honesty, it’s lush, nuanced, and incredibly smooth.
Still, cold-brew does have its critics (myself at one time included). Naysayers complain that cold-brew lacks the body and complexity of flavor of a heat-extracted brew. Over the years I’ve tried to extract more richness and complexity from cold-brew coffee, in the hope of achieving the best of both worlds. I’ve tried a number of out-there techniques including an initial hot water bloom (there’s that heat again); pressurized brewing in a cream whipping canister; near-continuous agitation; and five-day-long extractions in the fridge. But none of these techniques improved my cup of cold-brew. What they did was turn a simple, satisfying process into a chore.
After reconciling my love of cold-brew with years of heat-focused culinary indoctrination I am now ready to pass along my own commandments on how to make good cold-brew coffee. I promise not to yell.
Step #1 ROAST IT
Step #2 ▼
I use medium roast beans (left), which have been heated to a lower temperature than dark roast beans (right). Medium roast tastes more like coffee beans and less like the roasting process.
Step #2 GRIND IT
Step #3 ▼
I grind my beans fine. Most cold-brew recipes call for medium-coarse or coarse ground beans, but that’s a mistake. The factors with the biggest impact on coffee extraction are water temperature, grind size, extraction time, and finally, agitation—in that order. Since I use room-temperature water I can scratch temperature off the list of variables and grind size becomes most important. Finer particles will release more flavor compounds than larger ones.
Step #3 POUR IT
Step #4 ▼
I combine room-temperature water (usually filtered, as my tap water doesn’t taste great) and freshly ground coffee in a large French press. The press makes it’s a snap to separate the concentrate from the grinds after brewing.
Step #4 STIR IT
Step #5 ▼
After about 10 minutes, a solid raft of coffee grinds will form on the surface. I find it important to stir this raft into the water to maximize contact with the ground coffee.
Step #5
Step #6 ▼
This is the one and only time I stir the cold-brew. As I mentioned before, agitation is last on the list of factors affecting extraction. I find it a nuisance to stir a batch of cold-brew multiple times over the course of a day; the good news is I don’t have to.
Step #6 COVER IT
Step #7 ▼
Next, I cover the French press with plastic wrap and let it sit at room temperature for 24 hours (give or take an hour in either direction). I’ve done room-temperature brews as short as 12 hours and as long as 72 hours. Twenty-four hours is consistently the sweet spot.
Step #7 PRESS IT
Step #8 ▼
After 24 hours, I remove the plastic wrap and press the grinds to separate the concentrate.
Step #8 FILTER IT
Step #9 ▼
Then I pour the concentrate into a coffee filter-lined fine-mesh strainer set over a large measuring cup or pitcher. Some would say that this filtering step is optional, but I don’t like silt and grit in my cup. Most of the concentrate will filter through unaided, but I find it helpful to gently clear the sediment with a rubber spatula to let the last few drops through.
Step #9 DILUTE IT
Step #10 ▼
Finally, I dilute the concentrate one-to-one with cold water and pour it into a glass with plenty of ice.
Step #10 SALT IT
Now, instead of reaching for the sugar (which is unnecessary with super-smooth cold-brew) I stir in a pinch of Kosher salt. Just trust me on this one.
About the Author: Dan Souza
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Can the concentrate be combined one-to-one with hot (or boiling) water, and then slightly microwaved to warm it to serving temperature, or does this work best for iced coffee?
This is the same method as the Toddy Coffee Maker, which has been around for a very long time and makes an excellent Cold-Brew coffee
For ‘BoilerBrewer’ above – I keep my jug of concentrate in the fridge then just add water and microwave on about 75% power to heat – I had learned ‘somewhere’ that heating coffee too hot is what makes it bitter, so I try not to overheat it -
I’ve used a method similar to this for ages and have always enjoyed the coffee it produces. Typically I’ll reach for the milk jug instead of the water, making super cheap at home iced “lattes”.
Also, for what it’s worth, I’ve never had much success with doing cold brewed flavored coffees. Those always turned out tasting like over extracted mud.
What’s your ratio of beans to water?
Hi Justin – Check out the recipe under “Make it Now”:
http://americastestkitchenfeed.com/recipes/homemade-cold-brewed-coffee/
“The ratio of water to coffee is 1:1 by volume and roughly 4:1 by weight.”
Let us know how it goes!
I looked for a recipe button, I swear. Now I see it.
Thanks for your help.
IMHO (ha!), I make the best coffee ice cream ever with cold brew. Mix 1 1/2 cups cold brew (DON’T DILUTE!) with 2 cups cream and 1 can of sweetened condensed milk. Freeze per your ice cream maker’s instructions. YUM! For extra special goodness, make some toffee, crunch it and toss it in there too….
I’ve become addicted to cold brew coffee. Over at Upright Coffee I even built a Cold Brew Iced Coffee tap system so we always have our cold brew on demand. I even chill the iced coffee before leaving the tap so it doesn’t get watered down when it hits the ice.
http://uprightcoffee.com/cold-brew-iced-coffee-tap/20110902/
Made cold-brewed “coffee syrup” years ago with a container and filter made for doing just that. Used it on camping trips, diluting it with hot water. It was the most delicious coffee! So glad to see this discussed again!
To address the problem of watered down iced coffee, my brother in law gave me this tip; freeze some of the coffee in an ice try and use coffee ice cubes instead of regular ice cubes.
My New Orleans college roomie would bring a jar of cold drip back from her trips home. We’d heat up our milk and add the cold coffee. It was the best ever and I can’t wait to get started with this recipe.
I need to know how to make this quality iced coffee in large quantities. I work 3rd shift and love me good coffee at work. Right now I just pour freshly brewed hot coffee directly onto ice with some sugar, but I’d like to upgrade to your method making 10-12 cups at a time any suggestions?
Everyone – Thanks for the great discussion on here! I love getting feedback and tips from passionate coffee drinkers. I’m currently tinkering with the recipe before it gets published in our upcoming DIY cookbook and am looking at ways to improve the yield. Stay tuned.
Shawn – I’d follow the ratios posted in the recipe, mix everything in any large container, and then strain it through a few layers of cheesecloth before passing it through the coffee filter.
Wow I couldn’t even wait the full 24 hours (only did about 20) and it’s THE best iced coffee I’ve ever tasted. I don’t understand why you dilute it though. I found that the melted ice watered it down enough, if I added any water it was just lame and barely recognizable as coffee thanks so much for the instructions!
I followed the recipe, and it resulted in slightly less than 2 cups of coffee extract. I used 1/2 cup of extract to make a coffee diluting it about x2~3 times and adding milk.
$20 worth Stumptown 1 pound bag made 4 coffee cups, not like 30 cups.
What did I do wrong here?
Does anyone know if the cold process results in more – or less – caffeine than the hot? I’ve been making this for years, and just soaked it in a used plastic bottle, but recently switched to the French Press. It’s a much more convenient process. I don’t ruin it with sweetener, but I’m looking forward to trying the salt. I drink it cold at work and travel, but heat it in the microwave at home for a delicious cup of hot coffee in morning and even make it with decaf to ease back on my total caffeine. I save money by using an inexpensive ground coffee, but prefer the 100% Columbian version. I have used fancy coffee drainers for the filter, but just use a funnel now.
I just tried a small batch of this as a sample, and it turned out very well. I started a bigger batch today. Thanks for spelling it out so clearly in this recipe. I’m hoping some of the unpleasant side effects I get from regular brewed coffee will be lessened with cold brew. That is my experiment. Delicious first cup!
Pete – from what I know (according to the fine folks at my local Caffe Vita), cold brew has a lot more caffeine than hot brew. It also has much lower acidity, which is why I started drinking it. I first started drinking it at Caffe Vita as ‘Kyoto coffee” brewed in an “oji” and quickly learned that I could not drink nearly as much as its hot counterpart much if I didn’t want to be completely spastic all morning
Looking forward to trying the homebrew.
@jade-Dry coffee grounds will absorb water reducing the yield. I have a 4 cup (32 oz) French press and used 2 cups of medium fine grounds. I will let you know what my yield is tommorow.
I have used a Toddy Maker for years (appears my soon to be ex has taken it) and I always make a second “press” meaning I use the same grounds with half the water volume. I let the second sit for up to 30 hours. I then combine all of the yield together and it makes a great iced coffee using a 1:1 ratio of milk and coffee and a squirt of Hershey’s dark chocolate syrup. YUM! I will try the second “press” and post the results.
@klongmartin-do you use any sugar in the ice cream recipe?
Oh, another person who puts salt in coffee!!!
Many years ago someone taught me the trick of putting a pinch of salt on top of the ground coffee when brewing a pot to give it a smoother, less acidic taste; and ever since, if I’ve ever gotten a “sour” cup of coffee, I’ve put a little bit in to make it palatable…I’d never thought about putting it in a GOOD cup of coffee, though! Ha ha! (Off to try it right now!)
Why do the grounds of some brands of coffee float in the water and the grounds of other brands sink?
I understand that brewing cold creates a less bitter coffee, that is more tasty cold. But the forethought / time isn’t always there to prepare.
I have had good luck filling a mason jar with fresh brewed coffee from the press in the morning, and putting the jar lid off in the freezer for 2 to 4 hours. A sheet of ice forms over the top, but it doesn’t become solid, and the coffee pours through the ice making it extra refreshing. Also the mason Jars have good lids if you need to grab and go.
One thing I’d be careful with is using a glass French press for this method. Go slowwwww and if it gets stuck, don’t apply pressure. The mechanism on a French press isn’t designed for finely-ground coffee; if your filter gets clogged with fine grounds and you apply too much pressure, you can break the glass.
Otherwise, I am totally trying this sooner than later.
Instead of a French Press, try the Aero Press: http://aerobie.com/products/aeropress.htm – it uses lab-type filters so no grounds will get in the pressed coffee and the 2nd filter step will be moot.
This looks awesome, like the effort really pays off. I liked the phrase “pitch perfect bitterness”… my kind of foodie! Also the salt at the end sounds like my kind of finish. Thanks for sharing, I may buy a french press just to try this!
The HourGlass coffee maker is the best brewer for cold brew. makes 16 oz of extract and 16 oz of rebrew for iced coffee or it can be warmed. Once you use cold brew with its result being less acid you will not want anything else
Hario makes a great product called the Mizudashi. Check it out. It’s so much easier than any method I’ve seen. And it even looks nice. http://hariousa.wordpress.com/2009/11/01/how-to-use-the-mizudashi-pots-enjoy/
I have tried this with great results. I am no searching for the best grounds to make the brew, I have been told lighter roasts work the best.
Dan, we all appreciate the article, however, it leaves several things dangling, that I would very much like to hear about. I personally would be highly appreciative of your experience and experimentation. You mention 4 important factors, but neglect what effects 3 of them produce.
•How does temp affect the brew? What does steeping in the fridge do/not do?
•Does a longer steep (2 days perhaps) taste different a shorter (12 hours) one? How so?
•Agitation: What may or may not be acomplished by constant, or at least, repeated agitation?
The article was a good read, but it failed to answer questions that I wanted info on. You’ve told us how you have tweaked your brew to your liking…but we may have different tastes. A followup article would be much looked foward to
Great article. I have found that the Fridge Barista cold brew coffee maker is the easiest and best that I have tried for making cold brew coffee. It brews, stores and serves all in one container. No filters or corks to loose. Oh, it is also the cheapest. I bought mine online.
William: freshly-roasted coffee has lots of CO2 and some volatile compounds. These start to leave the coffee in a hurry when it is ground, which is why coffee snobs insist that you should buy whole beans and grind right before brewing.
If the coffee is fresh, the grounds will not only float initially, they will “bloom” and form a raft of bubbles that suspends some of the grounds above the water. (I haven’t tried Dan’s method yet, but when I hot-brew I pour in the water and then dunk the bloom with the back of a spoon until it has no grounds init.)
If the grounds sink with no encouragement it is likely that the coffee is older.
I use the Toddy for this. Works like a charm. My one bit of advice is to skip the paper coffee filters and get one of those reusable gold filters. Absolutely no sediment, no stirring and at a fraction of the time it takes paper filters.
Dan, Can you comment on the possibility of oxidation occurring during the RT rest resulting in some stale flavors.
@LoPan12
How does temp affect the brew? What does steeping in the fridge do/not do?
- The colder you go the less you are going to pull from the ground coffee (bitterness, aromatic compounds, etc.) and the longer the brew time. I tried a fridge batch next to my RT batch and found the RT batch a bit rounder and fuller in flavor. That said I know lots of shops that do it in the fridge for up to 48 hours and get solid results.
Does a longer steep (2 days perhaps) taste different a shorter (12 hours) one? How so?
- Yes, the longer you steep the more intense the concentrate, but I found my longer-brewed batches (48 hours and up) had a tendency to taste stale and sour. 12 hours at room temperature tastes under-extracted to me.
Agitation: What may or may not be acomplished by constant, or at least, repeated agitation?
- Agitation can speed infusion (http://www.cookingissues.com/2011/05/03/tea-time-cooking-issues-as-art/) but it doesn’t cut much time when you are working at RT. And it’s just a pain to do.
@Matt
There is certainly some oxidation taking place at the intersection of the coffee and the air. Batches in the fridge would also be affected by oxidation. In my taste tests I couldn’t detect noticeable oxidation off flavors until the roughly 48 hour point.
I learned to make cold-brew in Peru where it seemed to be the dominant method (along with powdered instant decaf, yech). I mix a pound of course ground fresh organic coffee with a quart of water. Then I add another quart and mix again. Then add two more quarts. Cover and let sit (sometimes I give another stir in an hour, sometimes I forget) for 24 hours. I then filter through a strainer and then a gold filter. (Even so, there is always a bit of “sludge” in the bottom of the gallon. I don’t mind it; my wife does not like the grit in the last cup of the concentrate.) Makes 3+ quarts of concentrate. We keep it in the fridge and dilute 1:3, conc:water. I microwave a cup in the morning to about 180. My wife adds water and milk and microwaves to about the same temp. I also make ice cubes from diluted coffee for iced coffee. We go through the 3+ quarts in about 5 or 6 days
The whole process takes a lot less time, in total, than making coffee every day and it tastes better.