By Dr Stuart Farrimond

Published: Saturday, 17 December 2022 at 12:00 am


The science of making cocktails has evolved in recent decades. Gone are the bleary-eyed kitchen parties where drunken revellers slosh together random selections of alcohols, stick a cherry and paper parasol in it and call it a cocktail – there is now some serious science to blending liquors, dubbed ‘mixology’.

Alcohol (aka ethanol) is a deeply unpleasant, toxic substance that irritates the mouth and sends a harsh burning sensation rushing up the nose. It’s a poison that needs mellowing. Hence, we have cocktails. 

WARNING: REMEMBER TO ALWAYS DRINK RESPONSIBLY

What alcohol percentage should you use?

An analysis by chef and bartender extraordinaire Dave Arnold, revealed that the average alcohol concentration of the world’s favourite cocktails was 15-20% ABV, sugar concentration was 5-9g/100ml (equivalent to about four sugars in a cup of tea), and acidity was somewhere between a Honeycrisp and Granny Smith apple (equivalent to 0.7-0.9 per cent solution of citric acid).

If you want to throw something together following these tried and tested ratios, mix two parts of high-strength alcohol (gin, vodka, whisky, rum) with one-part sugar (or maple syrup) and one part of sour (lime or lemon juice). A daiquiri, for example, can be made with two shots of rum, a shot of freshly squeezed lime juice and a shot of sugar syrup (one part sugar to one part water by weight), shaken with ice and poured. 

Ice is key

Ice is a key element of a cocktail, but it isn’t just for looks – it both dilutes and has a powerful chilling effect. As ice cubes melt, they suck up heat from the surroundings; a single 50g ice cube has 2000 watts of supercooling power in the ten seconds it takes to dissolve in a vigorously shaken cocktail.

Incredibly, if you energetically clatter your iced Christmas cocktail in a shaker for over 12 seconds, the liquid that pours out is an icy -4C! This coolth has a blissfully refreshing and numbing effect, further softening alcohol’s bite.

Flavour pairing

For flavours, we can turn to flavour-pairing theory. This is based on the principle that flavours that harmonise well (red wine/red meat, tomato/basil, pork/apple) do so because they share many flavour compounds. By analysing flavour compounds in different ingredients, we can predict pleasing combinations. Applying these principles with some Christmassy twists, here are my three festive cocktail suggestions to dazzle you and your guests…

Try these three cocktail recipes

Santa’s Snowball

The most famous of Christmas cocktails, the snowball is a mixture of advocaat, lemonade and lime, although it has the alcohol content of an alcopop (7% ABV), making it more of an alcoholic lemonade than a cocktail. Advocaat is an egg and brandy liqueur, invented by the Dutch. It makes for a rather sickly drink, so to knock off some of the acidity and up the alcohol content, I’ve added some Cognac.

Pour the advocaat and Cognac over ice in a glass of your choosing, add the lemonade and stir. Add lime juice, giving a final stir.

Chocolate Cracker

If you make this cocktail, opt for chocolate-flavoured vodka (38% ABV), rather than a chocolate vodka liqueur (28% ABV), which will be sweetened. The acidity comes from lemon or lime juice, while salt increases flavour perception, as well as the sensitivity of sweetness receptors.

Mix all the ingredients in a glass with four ice cubes and stir well. Strain into a glass containing a cube of ice. Garnish with coffee beans, crystallised ginger or a cinnamon stick, all of which are strong flavour pairings to chocolate. 

Festive Martini

The classic martini is a mix of gin (or vodka) and vermouth, typically served with an olive. The name has come to mean anything served in a martini glass, and this creation is no different. Using vodka or gin as a base, it combines the fruitiness of cranberry juice with the tang of lime, and the orange notes of Cointreau.

Shake with ice and pour into martini glasses rimmed with sugar, then serve with a curl of orange peel.

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