Cold brew coffee #FTW

By Michael Argentini
Managing Partner, Technology and Design

Drinking coffee in our business is almost muscle memory. The first thought after waking is usually about "coffee". And as we explore the world of coffee through the lens of cartridges (like Keurig and Tassimo single cup brewers), we begin to realize just how much we're missing. They may not provide the best coffee, but they certainly give us a quick dose of variety.

Enter Starbucks and other boutique coffee chains. This helps provide the variety of coffee we need at this stage. We get the next step up in quality and sometimes variety. They don't give you the world's best coffee, and they're expensive. But we love it nonetheless. We love it like other guilty pleasures.

Of course, brewing espresso at home in a tiny Italian pot is something we try along the way too. It's really good. It's pretty easy to make. It's concentrated. And it's a timeless classic. We may even graduate to a fancy espresso machine. But we plateau.

Inevitably we all end up here: cold brew coffee.

So why even bother? Check this out:

  • It tastes more like coffee smells. More of the essential oils are extracted. And there's more natural sweetness.
  • It's not nearly as acidic so it doesn't stain your teeth as much as hot brewed coffee, and is easier on the stomach.
  • It's concentrated. It can be used straight up as a cold shot or served as iced coffee.
  • It can be used in a mixed drink. It's great with vodka.
  • It can be diluted in hot water for a traditional Americano style cup of coffee.
  • It can be stored for a week in the refrigerator.
  • Killer for the environment. No cartridges are trashed. Very little disposable waste. And the grounds are easily composted.

Are there any down sides? Sure. But just one: it takes 24 hours to brew.

So make some.

Here are some easy recipe steps you can follow to make some of this magic elixir. It will yield about 78 ounces of concentrate (when mixed with water, it's equivalent to about 30 8-ounce cups of brewed coffee).


  • 20 ounces medium grind coffee (Hawaiian Kona or Koloa is recommended)
  • 1 gallon of cold or room temperature water


  • 1+ gallon pitcher
  • 1-2 unbleached paper coffee filters (cone style)
  • 1-2 bleached (white) coffee filters (cone style); optional
  • Sieve
  • 2 34oz (1,000ml) swing top bottles
  • You may need an additional container for overflow. This recipe makes a little more than two bottles can hold.


Steep the coffee overnight by placing the ground coffee in the pitcher and cover with enough cool water to fill the pitcher. Stir as little as possible to make sure all the grounds are wet. Cover the container and let sit on the counter for 24 hours.

DO NOT STIR. Agitation causes powder to be released as the grind rubs together. This will make your coffee cloudy and hard to filter.

After about 2 hours you should gently submerge the coffee grounds. Before they can absorb water, the grounds will float, forming a muddy cap above the dark water below. At this point, use a large wooden spoon to push the grounds down into the water. You may need to gently stir, but eventually the grounds will give way and begin to mix with the liquid. Some dark foam may sit on the surface. That's fine. At this point you may be able to add more water as well. Do so if the blended mixture has lost some volume as the grounds absorb water.

After about 6 hours you may notice some dark foam at the top. It's actually made of fine particulate coffee grounds. You can scoop that out to speed up the filtering process later on. Remember, don't stir or agitate the liquid if at all possible.

Strain the coffee concentrate. Place the sieve in a bottle. Line the sieve with a coffee filter, and then wet the filter with water. This will save coffee and prime it. Carefully pour the coffee liquid into the sieve, stopping whenever it gets too full.

Let it sit undisturbed until there is no more liquid dripping through the sieve, which can take a while. After it drains, discard the paper filter and repeat the process. When one bottle is full, proceed to fill the second. You'll get a little more than two bottle's worth.

PRO TIP: First, filter with bleached white paper filters into a large container, since these filters allow more particles through (the bleaching process makes them more porous). Once all coffee is filtered this way, filter a second time into the bottles with unbleached (tan) paper filters, which catch much finer particles. Double filtering the coffee is worth the extra time. The clarity and taste difference are noticable.

The coffee concentrate should not be cloudy. It should be clear/translucent in color, as in the photograph below. It resembles brown wine. If you get this result, you win.

Compost the grounds. It makes a great soil additive.

Store the concentrate in the refrigerator for up to one week.

To serve hot...

When you're ready to make hot coffee, bring the appropriate amount of water to a boil. Use a ratio of 1 part concentrate to 2 parts water, but experiment to see what tastes best. At this ratio, I usually pour out 3 ounces of concentrate into a large mug and place it in the Keurig machine and add 6 ounces of hot water for an amazing Americano. The flavor is very similar to my favorite medium roast, Black Blood of the Earth (see below).

What's next?

If cold brew coffee is up your alley, you'll definitely want to explore the next level: cold brew, vaccuum extracted coffee. This brings the cold brew experience to new heights. Not only are the beans cold brewed, but every last drop of oil and caffeine is sucked out of the beans, leaving them as dry as when they went in. The resulting concoction has 40 times more caffeine than an equivalent cup of coffee, and a totally unique flavor profile, without the acidity and bitterness.

To experience this coffee nirvana you'll have to purchase it from Funranium Labs. It's named The Black Blood of the Earth and it's no joke. They recommend that you drink no more than 100 ml (3½ oz) per day. According to their website:

The Black Blood of the Earth (or BBotE for short) is a cold vacuum extraction coffee concentrate. It was created by a diabetic with a sweet tooth out of his need for caffeine but without adding sugar and cream to cover the bitterness. While the goal was to make a rich, flavorful coffee full of delicious oils, caffeine was also concentrated as a pleasant surprise. According to back of the envelope rough estimates, the caffeine was concentrated about 40 times higher than normal drip coffee... so, drink responsibly. I recommend consuming no more than 100ml per DAY (3.5oz approx.)

You can purchase BBotE at their online store. They ship every so often, dependent on the availability of beans. But it's worth the wait.

On that note, it's time for me to grab a cup of coffee. I suggest you do the same. :)

Article last updated on 4/21/2018

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