Infusing liquor is the secret to a lot of great cocktails. You can add rosemary to rum. You can add beef to rye whiskey. The possibilities are endless, but one thing is constant. It takes a long time. Days—even weeks—sealed in a jar.
But there's a trick used by infusion masters. It takes mere minutes, and the flavour profile comes out almost exactly the same as a full infusion. The device is so effective, they call it "the time machine." Here's how nitrous oxide makes it happen.
It's the weekend and it's time for Happy Hour, Gizmodo's weekly booze column. A cocktail shaker full of innovation, science, and alcohol. I think this rum would pair nicely with some nitrous oxide.
The secret is the iSi Cream Whipper. As the name suggests, it's for making fresh whipped cream. You simply pour in the cream, pop in an N2O charger, release the nitrous oxide gas into the cream, and presto, you've got whipped cream. Infusing booze works almost exactly the same way.
- 1. Pour your booze into the reservoir.
- 2. Add in your flavouring agents. Then screw the top down to seal it.
- 3. Screw in the N2O charger until the gas releases into the bottle. Let it stand for one minute.
- 4. Replace the N2O charger with another one, pressurise, and then shake it for one minute.
- 5. Using two glasses to catch the spray, slowly release the pressure using the iSi's trigger (see video). Reserve the liquid.
- 6. Unscrew the iSi, and pour the liquid through a strainer into an awaiting vessel.
What was perfectly clear rum, after a basil and orange peel infuser, became a cloudy yellow. It also got incredibly delicious. I could have poured it over ice and sipped it. However, mixed in a daiquiri, infused rum took on a new dimension. I generally find daiquiris too sugary and boring. But the basil cut the sweetness and added depth and complexity. It was terrific.
Some infusers use CO2 as an alternate, but there are a couple of reasons to use N2O instead. For starters, as Sother explains, you can get much more pressure into the bottle with N2O. That pressure forces the alcohol into the cell walls of the flavouring agents. When the bottle is depressurised, the alcohol rushes back out again, and it carries those flavors with it—that's what you normally wait for weeks to happen using a maceration.
The other reason to use N2O is that it adds less flavour that CO2. CO2 puts a little bit of carbonic acid to the mix, which is why sparkling water cocktails taste a little bit sour. You don't want that muddling up an infusion.
Once you get your hands on an infusing tool, you can experiment like crazy. The starter model iSi chargers range between £40 and £100, so it's a pretty accessible way to alter a cocktail. Add dark chocolate to bourbon? Sure. Hot chilis to vodka? It burns—but why not?
In fact, this is the same method used by major producers of bitters when they're trying out new flavours. It's a huge saver of time and money. When Bittermens made us some custom coffee bitters for The Angry Ginger, they used the iSi, and they turned out great.
Once you've found ratios you like, then you can move on to bigger batches, either shooting them with the whip-it all at once, or let them slowly soak to bring out the full flavour. Or you can just keep on experimenting forever, once glass at a time. The world is your infused oyster. Hmm...chilled vodka with a PEI oyster infusion?
Sother Teague is a former R&D chef for Alton Brown on Good Eats (Food Network) and instructor at NECI (New England Culinary Institute). He is currently consulting chef at Consulting at Proletariat (a rare, new and unusual beer bar) and the Bourgeois Pig's Brooklyn location. He is also a barman at Amor y Amargo, Prime Meats, and Booker & Dax. Follow him @CreativeDrunk on Twitter.