Cold brew coffee has recently gained a massive following for its incredible smoothness and delicious flavor. Irish coffee, being caffeinated and alcoholic, has been popular for even longer. Too bad Irish coffee usually tastes like an 80-proof mug of acid.

But, with careful experimentation in the Gizmodo laboratory, we've discovered a way to produce a chemically balanced coffee cocktail that tastes wonderful. Introducing The Morning After, a Gizmodo original.

It's Friday afternoon, you've made it through the long week, and it's time for Happy Hour, Gizmodo's weekly booze column. A cocktail shaker full of innovation, science, and alcohol. It's one hell of an eye-opener.


Confession: This recipe was born out of a nasty hangover. I was walking down the street one morning after a late night and I found myself torn between wanting a cold brew coffee and an Irish coffee. I wanted both, but simply adding a shot of Jameson to a cold brew would make it too watery. That method brings out the worst parts of each drink's flavors.

So I thought about how cold brew is made—simply immersing the ground coffee in water until the flavor slowly blooms. Then, I considered how alcohol is such an efficient flavor extractor. I had an idea: What if I just traded whiskey for water in the cold brew extraction process?

After considerable effort experimenting with ratios, brewing times, temperatures, and ingredients, I arrived at something delicious, boozy, and highly caffeinated.

Cold Brew Instructions

  • 1. Measure out three ounces of fresh medium-roast coffee beans. Grind them medium-to-coarse, then place the grinds in a French press. Note: If you don't have a French press you can use a mason jar.
  • 2. Measure out 12 ounces of Jameson. Pour the whiskey over the coffee grounds. This 4:1 weight ratio will always yield consistent results. However, if you don't have a scale, use a basic cold brew rule—a 1:1 ratio by volume.
  • 3. Give it a quick, gentle stir to ensure that the grounds are properly distributed in the solution. Then cover the top of the French press with some cellophane or a baggie and seal with a rubberband.
  • 4. Let it sit, undisturbed, overnight. How long you should leave it will depend on the darkness of your roast and how finely you ground the coffee. 12 to 16 hours seems to be the magic range. The longer you leave it the more bitter it will be.
  • 5. Use the French press to separate most of the grounds, then pour the extract into a glass or a small jar. A French press will get you better yields (we got a full 8 ounces of extract), but if you don't have one, just continue to the step below and add a little squeezin'.
  • 6. Pour the liquid through a paper coffee filter held over a jar.

Congratulations, you now have cold brew Irish coffee extract. It will keep in the fridge for two weeks without any noticeable change in its flavor profile. It will remain usable for up to six weeks (alcohol is a remarkable preservative). But for heaven's sake, do not drink the extract straight! It's bitter as hell. Here's what to do with it.

Recipe for The Morning After

  • 2 ounces cold brew Irish coffee extract
  • 2 ounces cold water
  • 1 teaspoon brown sugar
  • heavy cream (or whipped cream) to top
  • 3 ice cubes (aprox.)
  • 1 pinch kosher salt (optional)
  • 1 fresh mint sprig (optional)

Pour the extract into a tumbler, followed by the cold water and brown sugar. Mix with a spoon until the sugar dissolves. Add the ice cubes and stir a bit to melt them. You could stir in a small pinch of kosher salt—this brings out some of the more subtle flavor, but it's not for everyone. Top with heavy cream (whipped, ideally), and add a sprig of mint.

Cold Brew Irish Coffee: The Best Part of Waking Up Drunk

The end result is a very smooth, flavorful drink, perfectly pH-balanced between the alcohol and coffee. If done well, neither the coffee or the whiskey will have a distinct aroma as you're drinking—but rest assured, those two ounces of booze are in there, and a cold-brew/alcohol combo is a very effective technique for extracting the beans' caffeine. In other words, it's a strong way to start a Sunday morning.

The Morning After can be made as a hot drink as well—similar to a standard Irish coffee, but smoother and with lower acidity. Just trade 4 ounces of hot water for the cold water and ice in the recipe above. This version seems a bit more alcoholic than the cold drink (despite the fact that it's more diluted). That's because some of the alcohol evaporates in the steam, which you breathe in as you sip.

With either recipe, please be careful. Alcohol and caffeine can be a dangerous combination. Let's not forget about Four Loko, and it's evil spawn Faux Loko, the DIY drink I should never have told you how to make.

As far as I know, this is a first. Take this knowledge, go forth, experiment, and enjoy. Check back next week for another boozy-sciencey Happy Hour.

Video by Michael Hession.