Shaken, not stirred

Photo by Aditya Saxena on Unsplash

The martini: London gin, French or Italian vermouth, olives from the Mediterranean and American glamour. It could have been Cosmopolitan but that name is taken. The name comes from the Italian vermouth brand of Martini & Rossi (the surnames of the founders). Likewise, the French vermouth, Noilly Pratt, is named after its two founders. Why Sig. Martini was singled out I don’t know, although why M. Pratt was not is perhaps clearer (I can’t see James Bond ordering a dry pratt with quite the same panache, although Roger Moore probably could).

It is only seemingly the simplest of the cocktails. Between the gin and the vermouth there are around 20 botanicals contributing flavor. Then there is the subtlety of the olive and its oils and salt, the ratio of vermouth to gin, serving temperature and, famously, the methods of shaking and stirring.

Issues of mineral content in the ice, whether the olive should be pitted or not (with or without pimento) and even the shape of the toothpick further add to the legend. Then there is the matter of replacing the olive with a twist of lemon.

Before you know it, it’s not so simple a cocktail.

The etymology of the word cocktail is not known, but there are plenty of theories, including docked horses, cock-ales, egg cups and barrel dregs. Apparently, it should be pronounced coh-tail (as in Cockburn), although doing so adds pretension and I think the word looses some of its spirit (sorry).

The gin should be London. ‘London gin’ is a legal specification but not a geographic one, so Plymouth gin (which can only be made legally in Plymouth) is a London gin.

The French or Italian vermouths are both endorsed. The word vermouth comes from the German for wormwood (wermut). It is a fortified wine aged with botanicals that originally included wormwood, as did absinthe (wormwood’s botanical name is Artemisia absinthium). Thus, in earlier incarnations, a dash of absinthe might be added to a martini, as could other bitters (wormwood is bitter).

In the early 20th century, the ratio of gin to vermouth was 1:1. Steadily, as the century unfolded, the ratio of gin to vermouth increased (a world war, a great depression, another world war and then the threat of nuclear annihilation might help explain that). By the end of the century, vermouth had become almost optional, and martini’s were ‘dry’. A higher ratio of vermouth makes it a wet martini. The 1920s were probably its heyday, and the ratio was then about 5:1 to 6:1. A 1:1 martini is called a perfect martini — perfect the noun and not perfect the adjective. Likewise for the well-done steak.

Folklore ensures that the martini is, for certain generations at least, associated with the ‘shaken, not stirred’ commandment.

These two methods of mixing the drink can have different effects (see Dave Arnold). For a typical mix, the shaken will be colder and more diluted with water than the stirred. This is because cooling and dilution occur by the same mechanism — melting ice. The ice will melt faster when shaken.

melting = cooling = dilution

It takes energy (heat) to melt ice, and this heat is taken from the warmer liquid. The ice, at 0C, doesn’t heat as it melts; it uses the energy to change from the solid to liquid states (heat of fusion). The amount of energy needed is substantial, hence ice is effective at cooling — so effective that it can cool to below zero if there is alcohol in the liquid. How does it do that?

It has to do with disorder. In physics, entropy is the measure of disorder, and entropy always — and I mean always — increases. Or, to put it simply, ‘if you think things are mixed up now, just wait’.

It is this fundamental law of thermodynamics (entropy must increase) that guarantees the end of the universe. Think about that when you’re sipping your next icy martini. Discuss.

Entropy (disorder) is greater in a liquid, where molecules randomly flow around one another, than in a solid, where they are locked in place. In water-alcohol-ice mixes, ice (at 0C) can melt by taking heat from the liquid, while the liquid can keep cooling below 0C because of the alcohol. This goes on until the entropy gained by melting ice is about equal to the energy needed to produce that gain. Then the system is in equilibrium for a while (until the whole system comes up to room temperature). If you’re shaking the mix, this will take about 15s (how convenient is that). At the end of that time the mix will be about minus 7C. Perfect.

A stirred martini will reach this temperature (and dilution) eventually, but if stirred for the same amount of time as it would have been shaken, it will be warmer and less diluted, simply because shaking melts the ice quicker. Dilution is not a bad thing, and can enhance flavour.

Shaking also introduces air into the drink and alters texture, as do small unfiltered ice shards, which may or may not be desirable.

Folklore requires a martini to be shaken to the rhythm of a waltz, its close relative the Manhattan (whisky and vermouth) to a foxtrot. Sadly, this doesn’t make a difference. It should.

Ice straight out of a domestic freezer is at ~ minus 18C, however it rapidly comes up to 0C, and the cooling effect of this warming is not great, even though it seems like it should be (more physics). Ice in an insulated ice bucket sits at 0C, as does bar ice.

It will even matter how you stir. Side-to-side will be more like shaking because the relative velocity of ice surface to liquid flow is maximized. Stirring in one direction minimizes this. You can dissolve anything in water faster with a side-side stirring action, and it is more effective for whipping air into a liquid too.


Further reading:

Frank Moorhouse, “Martini, a memoir”, Knopf, 2005.



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