I remember a night working at Off Broadway in Hackney, many years ago, where an off duty bartender had brought in a shitake mushroom infused sweet vermouth that he was so proud of. He was begging us to put it into a Manhattan, so I did, and I am grateful to him for the idea, because I can now pinpoint the absolute nadir of my cocktail creating career, and know that the blame lies with someone else.

But, in his defence, sometimes we want a cocktail that tastes of something completely novel, a drink that isn’t bound by ‘bourbon’ or ‘gin’ or even the clean booziness of vodka. And sometimes we do want those flavours, but we want to make something concentrated with other flavours that don’t exist as syrups, sodas or liqueurs.

And sometimes we want Skittles Vodka.

In all those cases, the best thing to do is to infuse the spirit in our drink with something else. Now, it’s quite hard to do an infusion with less than around 500ml of a spirit, so we want to make sure that it’s going to be delicious, and something that will get used up. Do not stick mushrooms in there, is what I’m saying.

There’s three techniques we’ll cover today; a simple ‘leave it in the booze’ infusion, fat washing spirits with oily flavours and using nitrous oxide for delicate flavours. They all rely on one very handy aspect of ethanol, it being a fairly universal solvent. 

Flavour molecules come in all sorts of weird and wonderful organic chemistry types, but one thing they tend to have in common is that they are somewhat volatile; happy to flit from the thing you’re eating or drinking directly into your retronasal cavities where the majority of tasting happens. We know that the tongue only really discerns sweet, sour, bitter, salty and umami flavours, so when a sommelier is telling you that you’ll definitely taste slightly under-ripe Californian peaches in your orange wine, what they really mean is that you’ll smell them as you drink, and your pathetic brain will trick you into thinking it’s a taste.

Enough insults, onto the instructions.

Simple infusions

This one really is the most basic; take your material for infusing and whack it in your booze, then leave, strain out and you’re done. It works really well with dried herbs, fruit, vegetables, teas and in the recipe below, for salted peanut infused rum. When we steep something in alcohol, we’re pulling out all those great flavours, but we’re also letting the material start to break down, so it’s very important to taste your infusion and stop it at the point it’s ready…don’t just leave some cucumber in a bottle of gin and come back in 6 months, it will be grim. In fact, most infusions are at their best 4-7 days in: primarily because of the breakdown of plant cells due to alcohol/osmosis stuff, which leaches chlorophyll into the booze, leaving it tasting bitter and ‘stewed’.

A good rule of thumb is that you should have at least 10x the weight of booze as you do material for infusion, so for example, to make a very passable copy of Hendricks:

500ml Gin
Peel of one cucumber (roughtly 50g)
Pinch of salt
2ml Rose water

Add all that to a kilner jar, leave for 4 days, strain and have in a G&T. You just saved £20.

To make the EC Salted Peanut Cuba Libre, you’ll need:

1 bottle Havana Anejo Especiale
125g KP Salted peanuts

Let the peanuts sit in the rum for 24 hours, then strain through a muslin cloth to remove any particles. Do not, under any circumstances, eat the peanuts that have been soaked, they have been memorably described as having what you imagine the texture of baby teeth to be. Leave to stand for 24 hours then carefully pour into another vessel, leaving any sediment.

Salted Peanut Cuba Libre

Fat Washing

Taking advantage of Ethanol’s solvent properties, one brilliant thing we can do is strip the flavours from fats and oils. This was something PDT in New York was famous for, making Bacon infused bourbons for old fashioneds served with maple syrup (they, quite simply, fucking rule). Hawksmoor did something similar with their Full Fat Old Fashioned, infusing butter into the bourbon. At Every Cloud, we infused some lovely olive oil in gin for our clean dirty martini.

To do this, we’re going to stick to the 10:1 ratio again. You’re going to need some space in the freezer and something for straining the liquid when you’re done.

Olive Oil infused Gin

Mix the gin and olive oil either in a bag you can seal (zip-lock bags are great for this) or a container you have a lid for. Even a jug with some cling film on top is fine. Stir it every hour for a day to make sure the gin is really making contact with as much of the olive oil as you want, then whack the whole thing in the freezer for 24 hours. When you get it out, the oil will have frozen solid, so quickly pour the liquid through your strainer (you should keep the gin infused olive oil, it’s amazing with smoked salmon) and you now have olive oil infused gin, somehow perfectly clear. Try making a martini with that for a real treat.

If you want to try the butter infused bourbon, the proportions are the same as this, but use clarified butter or ghee to make sure you’re left with a clear spirit.

Nitrous Oxide infusion

You may be amazed to discover nitrous oxide has uses beyond 15 year olds snatching a momentary high by the swings in the park. We can use it to force booze into every nook and cranny of our infusing material, then when the pressure is released, it fizzes out, carrying all the flavour with it. What’s great is that the process only takes 3-4 minutes, so even with the most delicate fresh herbs there’s no risk of stewed or woody flavours. Personally, I’m a big fan of a basil daiquiri, but almost anything can be infused with this method and even if you end up over extracting the flavours, you can dilute back to the point you want without losing the definition. You will need a little bit of equipment, though; a cream whipper (ISI are the best brand) and some NO2 canisters. You can get these online or through most catering suppliers, though you may be asked what you plan to use them for. 

Basil Rum

Add to your cream whipper and seal, then charge with one canister. Shake hard for 1 minute, then leave for 1 minute before shaking again for a minute. Leave for one minute more then release the pressure by opening the nozzle (try and have a jug in place to catch any liquid that fizzes out). Once the pressure is released, you can unscrew the cream whipper top and strain out the leaves from the rum (it should now also be a lovely delicate green colour). It may still be fizzing slightly but nitrous oxide fizz dissipates in 5-10 minutes.

Now you know how to infuse stuff into booze, have a look around your house. Got some tired herbs? Whack them in vodka for your next Bloody Mary. Some leftover chillies could go into tequila for spicy margaritas. Grate a carrot into some scotch for amazing Penicillins. The world is your oyster (mushroom) infused vermouth, don’t bring it near me please.