How to Make Iced Coffee, Cold Brew & Everything in Between

How to Make Iced Coffee, Cold Brew & Everything in Between

Class is in session.
by Maciej Kasperowicz | April 05, 2019

The perfect glass is easier than you think!

The warmer months are upon us, and that means it’s time for everyone’s favorite cold coffee to arrive back on the scene! Cold coffee can get confusing, and I am frequently asked how to make iced coffee at home and cold brew, which is typically followed by “What is the difference between iced coffee and cold brew?” I’d love to set the record straight, and give you the knowledge you need to navigate the wild world of cold coffee. It’s surprisingly simple to make delicious iced coffee, as good or better than you find in a coffee shop, from the comfort of your own home.

Get started with your new favorite coffee!

homemade iced coffee with ice

How to Make Iced Coffee

First off, iced coffee is generally used as an umbrella term for all coffee that is cold. It isn’t a brew method or a roast profile, it’s an easy way to talk about coffee that tastes good with a bunch of ice cubes in it. Contrary to popular belief, it isn’t just leftover coffee poured over ice (even though baristas at coffee shops made it this way back in the day!). Within iced coffee are a few different brewing methods, mainly cold brew and flash chill.

Homemade cold brew coffee made in a Mizudashi Cold Brew Pot.

How to Make Cold Brew

Cold brew refers to coffee that is brewed using room temperature or cold water. Hot water can extract the particles of coffee out from the grind faster and more efficiently, which is why brew times are only a couple of minutes, and the coffee grounds usually resemble fine salt. When you use room temperature or cold water, it has to work that much harder to extract the particles of coffee, and therefore it has to sit in contact with the coffee for hours at a time. This is why the coffee grounds are coarser, to provide more surface area for the water to extract the coffee. If the coffee is ground too fine, overextraction can happen very easily, which will result in a coffee with a sharp coffee taste and a very cloudy cup.

> Cold brew generally doesn’t taste as acidic as hot coffee, because the extraction is much more gentle…

Because hot water can change the molecular structure of what it extracts from coffee grounds, you’ll notice that cold brew generally doesn’t taste as acidic as hot coffee, because the extraction is much more gentle. So even with the long extraction time, cold brew usually tastes smoother and less sharp. Since cold brewing is truly a brew method, it doesn’t have to be consumed cold. In fact, some people who like the thickness of the body and the smoothness of the taste heat it up after they’ve finished brewing it and drink it hot!

Cold brew is an immersion brew method similar to a French press, where coarsely ground coffee sits in water for an extended period of time. If you don’t have a way to make cold brew, like the Mizudashi Cold Brew Pot or our Cold Brew Bags, you can even make cold brew in your French press at home! Here's how:

  1. Prep a French press like you normally would, using about 1/3 more coffee grounds.
  2. Add room temperature or cold water instead of hot water.
  3. Let your French press sit overnight in your refrigerator. At Trade, we recommend 12 to 18 hours of brew time, with denser, more expressive coffee the longer the coffee stays in contact with water.
  4. Pour your cold brew into a tall glass and serve with ice cubes, milk, or cream to taste.
  5. Refrigerate leftover coffee for up to seven days
> Some people prefer the thickness and density of a cold brew concentrate, which also takes very well to cream.

One of the cool things about homemade cold brew is that you can make it in a ratio that is ready to drink, or you can brew a concentrate. Simply use a higher coffee to water ratio for a concentrate, and less coffee to water for a ready-to-drink option. The flavor notes of a concentrate will taste more dense and the body will be thicker than an iced coffee you might purchase at a coffee shop. However, it’s very simple to dilute the concentrate. Just add cold filtered water to the concentrate to adjust the taste however you like it best. Some people prefer the thickness and density of a cold brew concentrate, which also takes very well to cream or sweetened with flavors like caramel or vanilla. It’s also easy to add extra ingredients to the cold brew while it is steeping, for exciting and unexpected flavor notes. I like to throw in some orange peels or spices with the coffee grounds and let those delicious flavors slip into the cold brew. Sometimes I experiment with adding them at different stages of brewing, to play around with the intensity of the flavors. Traditionally, people use chicory root in their coffee grounds for a New Orleans style cold brew, which is delicious alongside a morning beignet — or a donut, if you will.

As you experiment, you can play around with grind size, water filtration, brew times, and different types of roast profiles and origins. You never know how a coffee taste will turn out when brewed a different way, so it’s fun to explore your options. For those looking for more classic or traditional cold brew flavors, look for medium to dark roasts with lots of sweet candy bar notes like chocolate, caramel, and nut. For more adventurous cold brew drinkers, naturals with their berry notes make for super-sweet cold brews and Kenyan coffees add a nice bright pop to any concentrate.

I like using a cold brew concentrate for the base of a iced latte, which is super easy. Add some cold brew concentrate to a tall glass, in a separate glass, or Boston Shaker if you have it, add ice and milk. Shake the ice and milk together to create a frothy texture, and pour over the cold brew concentrate for a special morning treat. You can even drizzle caramel or use vanilla syrup to really make something special.  

Funky and unique cold brew concentrates also make an excellent base for drinks. A cold brew concentrate made with a high-acid and cherry flavored Kenyan coffee makes an excellent base for a cold brew lemonade. The acidity of the lemonade is complemented by the acidity within the coffee, and the sweet fruity notes of the coffee really sing when paired with the sugar added to lemonade. It’s a fun, summery twist on an Arnold Palmer!

While cold brew is as easy to enjoy as it is to brew, there is still one potential drawback: oxidation. This can happen because cold brew is in contact with air for an extended period of time (it’s also what turns a slice of apple brown when it sits out on the counter for too long). You can cut down on oxidation by making sure you have a cover or lid on your cold brew while it’s brewing to limit the amount of air that comes into contact with the coffee grounds. You also want to make sure you keep your cold brew out of direct sunlight while it's brewing, as the sun can warm the water and influence the extraction of the coffee. The key is to keep it at a consistent temperature, out of direct sunlight. This is why many people will brew their cold brew in a refrigerator, which is great, but will also slow down the extraction a bit. It’s harder for the water to pass through the coffee at colder temperatures, so expect to add on four to six additional hours to your brew time if you’re brewing cold brew from the cool comfort of your fridge.

Flash-chilled iced coffee, also known as Japanese iced coffee, made in a Chemex.

How to Make Flash-Chilled Coffee

Flash chill is a brewing method where coffee brewed with hot water is rapidly cooled over ice. Popular with the pour over crowd and used to accentuate acidity in cold coffee, or the nuances of a single origin, flash chill is easier than it may initially seem. The taste is generally lighter and more floral, and some coffee lovers revel in how tea-like of a brew you can get. Sometimes very clean caramel notes emerge, and it’s really fun to see which origins taste different when brewed this way. Because it follows the same general ethos of pour over coffees, flash chill comes with endless potential for experimentation.

But before we get there, let's start with the basics. Here's how to make flash-chilled iced coffee, also known as flash brew and Japanese iced coffee after this method’s origin and popularity in Japan.

  1. Replace 1/3 to 1/2 of your brewing water with ice cubes.
  2. Pour your water slowly to make sure that you can accurately saturate the coffee grounds with the lessened amount of water you’re using.

To help you understand the ratio, let’s use an example: If your recipe calls for 100 g of hot water, replace 33 g of the hot water with 33 g of ice cubes, placed in the bottom carafe under the brewer. I recommend starting with this ratio, as it’s easier to pour 75 percent of your brewing water and extract all the good stuff coffee can offer, rather than starting out with only half of your brewing water. Slowing down your pour can also definitely helps in completely saturating the coffee grounds, ensuring your coffee is delicious as can be. However, some coffees will taste better with 50 percent of the hot water used, and more ice diluting the concentrated brew. It’ll take a little bit of finessing to figure out how to make it exactly the way you like it best, so stay patient and open to exploration while you brew.

My flash-chilled Chemex recipe requires two pulses of water. I prep my Chemex by wetting the filter and pouring out the water, as I normally do when making hot coffee. Next, I add 175 g ice to the Chemex and put a paper filter back on Chemex and add 50 g of medium-coarse ground coffee. I make sure to shake the Chemex to even and flatten the brewing bed. Then, I pour 140 g of hot but not boiling water in elliptical motions over the coffee bed, whipping the slurry into a vortex. I let the water drain completely (I know I agitated it correctly if the coffee drains into an inverted cone shape). Once the water has drained all the way down, I pour the remaining 140 g of hot water over the coffee bed. I start by knocking down the top part of the coffee cone, evening the bed once again, and once again pour in whipping, elliptical motions. Once the water drains all the way down, I remove the Chemex filter and stir the hot coffee and remaining ice together to dilute the brew and chill the drink down completely. What’s left is a delicious, clean, and simple iced coffee, ready for some summer morning sipping.

But you're not limited to the Chemex. Because this method mimics all the same techniques as hot pour overs do, you can make flash-chilled coffee in a Kalita, Aeropress, or literally any pour over device. You can even make flash-chilled coffee using your drip coffee maker!

To do so, follow the same ratio of using 2/3 of the hot water you normally use and replace it with ice in the carafe. If your coffee maker has a hot plate turn it off or remove the carafe as soon as your coffee has finished brewing. You run the risk of "warping" the taste by adding too many temperature variables throughout the brewing process. You also want to make sure that the hot coffee is what’s melting the ice, not any heat from below on a hot plate. That’ll just ensure a watery brew, which won’t taste as good.

The most important part of all of this, is to remember that it’s just coffee, so have fun with it! I often hear people getting tripped up or frustrated because their brew isn’t perfect on the first (… or fourth) go, which is understandable, but unnecessary. There are tons of recipes out there from your favorite roasters and at Trade, so let them guide you to the iced coffee of your dreams. Have fun and happy brewing — we can't wait to see the awesome creations you whip up!

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