Summertime in New Orleans feels akin to wearing a wet wool blanket fresh out of the steam room. Wait, you want some coffee? Great, let’s put a near-200 degree beverage in your hand. I kid, but some folks still drink hot coffee outside and all I have to say is “bless y’all.” For everyone else, the summer heat requires the sweet relief of an ice cold beverage. If you want to cool down, we’ve got you covered with a massive variety of iced coffee, espresso and tea. But sometimes you may simply prefer the convenience and satisfaction of brewing iced coffee at home. We can help with that, too!

In this blog I’m going to walk through the two most popular ways to make iced coffee, including the tools you’ll need to do it and specific and easy-to-follow instructions! Now I know some of you are thinking, “Jonathan, I just brew hot coffee and let it sit around until I can put it in the fridge, voila!” Okay, if that works well for you (i.e., you like bad-tasting coffee) then cool – you do you. But there’s a better way, my friend!

Decades of brew science have taught us that coffee contains delicious and necessary acids, particularly chlorogenic acids. These chlorogenic acids ought to constitute around 17% of your brew, and they contribute greatly to vibrancy, nuance, and fruit and floral tones. However, chlorogenic acid breaks down as coffee sits or cools slowly. As it degrades, it produces quinic and caffeic acid as a byproduct, both of which are associated with negative flavors in coffee, notably bitterness and astringency. You may have noticed this effect if you’ve ever left a pot of coffee out all day and then tasted it later. But even coffee that sits in well-insulated airpots will degrade, even if it remains at drinking temperature.

So how do you brew tasty iced coffee without the producing the astringent and bitter qualities of these acids? There are two ways: 1) rapidly cool the coffee immediately upon extraction; and 2) remove the heating element altogether. That’s exactly what we’ll tackle in the next two sections.

Flash Chilled Pour Over

The first method – rapid cooling – is often referred to as flash chilled iced coffee.  Simply put, it entails brewing coffee directly over ice. The rapid cooling traps the good acid, prevents the creation of bad acid, and results in a cup that’s light and vibrant with delicate notes intact. This is a great method for many African coffees, or simply those with an abundance of floral and citrus notes that may otherwise get lost in other brewing styles.

Want to try this at home? You’ll need a manual brewing device. We use Kalita Wave brewers in the shop, but you could similarly use a Chemex or other device you have handy. Just fill the carafe with ice using roughly half the total water volume you’d use normally. Then, use half as much hot brewing water as usual, and use a typical amount of coffee grounds for the total water volume. Get it? Same amount of H2O – just half of it is ice and half is brew water – and the same amount of coffee. The trick is to increase the fineness of your coffee grounds, thus a) increasing surface area, b) increasing extraction rate and c) increasing contact time during the brew cycle (i.e., slowing the flow rate).

Here’s a recipe to work from. Feel free to adjust for your brewing method, or to suit your taste. This is a pretty standard recipe that can easily be tweaked. (Fyi, we sell a book in our shop with loads of hot and iced coffee recipes for virtually all popular manual brewing devices … we also have a house copy that you can come peruse for free!)

Equipment needed: Brewing device, filter, scale, kettle, brewing ice and water, coffee

Step 1) Rinse the paper filter

Step 2) Measure 130 grams of ice (filtered water preferred) (crushed ice preferred, as it melts faster) and dump it into a carafe

Step 3) Measure 170 milliters of filtered water, and bring to a temperature of 200 degrees Fahrenheit

Step 4) Grind 22 grams of coffee marginally finer than you usually use for hot coffee

Step 5) Pour enough water into the coffee bed to saturate the grounds and allow them to “bloom” 30-50 seconds (until bloom rests or descends)

Step 6) Brew per usual (we recommend pulse brewing for the Kalita Wave)

When done, just allow the ice to melt with the brewed coffee and there you have it! If you’re already a manual brewer, this method is a small departure from what you’re used to.

Cold Brew

Even though we make flash chilled coffee at Mammoth Espresso, it’s not the only way to enjoy iced coffee at home. There’s is the relatively simple – albeit lengthy – cold brew method. When you make cold brew, you generally remove the heating element altogether (hence cold brew), which requires a significantly greater amount of time in order to extract enough compounds from the coffee. This method produces a big, sweet, sometimes nutty, low-acid coffee. It won’t be as nuanced as flash chilled for developing some delicate flavors, but excels with coffees that have a natural sweetness and depth. The resulting coffee is usually in a concentrate form. If you like rocket fuel then proceed as is, but many people prefer to dilute the concentrate to taste.

You can purchase special brewers just for making cold brew. The Toddy system has been around forever, but some household items work well (and are so much more fun!) and even your French press can do the trick.

Here’s a recipe. Again, tweak it to fit your needs for quantity or taste.

Equipment needed: gallon jug, cheesecloth (not previously used for cheese!), water, coffee

Step 1) Grind 340 grams of coffee to a medium-coarse grind

Step 2) Pour 85 grams of coffee into the jug, followed by 340 milliliters (same as grams) of water; let stand 5 minutes

Step 3) Pour remaining 255 grams of coffee and 1,065 milliliters (36 ounces) of water into the jug

Step 4) Let coffee steep for 12-16 hours

Step 5) Pour coffee through cheesecloth and into a decanter and refrigerate before serving

Once cold, you can dilute the cold brew with water or drink it as-is. I recommend trying a sip of concentrate first, then 1:1, then finding the ratio that works for you. Also, the brew time can be changed to produced different results. Some folks love this method stretched over a 24 hour period.

There are, of course, other ways to brew cold coffee – like the slow drip Kyoto, or Aeropress – but the methods described above are the dominant practices in the specialty coffee market right now. I hope this guide is helpful, and if you have any questions you’re always welcomed to stop by for a chat.

Photo credit Michael Tucker