How to Make an Espresso Martini (and Why It Foams)

An espresso martini is vodka, coffee liqueur, a fresh espresso and a little sugar syrup, shaken hard with ice and strained into a chilled glass. The International Bartenders Association's version is 50 ml vodka, 30 ml Kahlúa, 10 ml sugar syrup and one strong espresso, garnished with three coffee beans. The two things that make or break it are both about the coffee: it has to be fresh espresso, and it has to be shaken hard. That is where the famous foam comes from.

The recipe

1. Chill a cocktail glass.
2. Pull a fresh espresso. The espresso guide explains what makes a good shot.
3. Fill a shaker with ice and add the vodka, coffee liqueur, syrup and espresso.
4. Shake hard until the shaker is painfully cold to hold.
5. Strain into the glass. A fine second strainer catches ice chips and gives a smoother head.
6. Garnish with three coffee beans once the foam has settled.

The balance is easy to adjust. Less syrup or less liqueur gives a drier, more coffee-forward drink; more makes it closer to a dessert. Bradsell's original version used no liqueur at all.

Why it foams

The creamy head on a good espresso martini is not decoration — it is coffee chemistry, and it is the same chemistry as crema.

Espresso is brewed under pressure, which forces carbon dioxide from the coffee into solution and pulls out compounds that are very good at holding bubbles. In their review of espresso foam, Ernesto Illy and Luciano Navarini describe the stabilisers: proteins, which help foam form, and high-molecular-weight polysaccharides and melanoidins — the brown compounds of roasting — which keep it from collapsing. Coffee oils work the other way, destabilising foam.

Shaking hard does two things. It whips large amounts of air into the drink, and it chills it fast. The foaming compounds from the espresso coat the new bubbles and hold them, which is why a well-shaken espresso martini wears a pale, dense head that lasts while you drink it.

That also explains the common failures:

• Old or weak coffee carries less gas and fewer of those compounds, so the head is thin. The crema section of the espresso guide explains how fast coffee loses its gas.
• A gentle shake does not whip in enough air.

Where the drink came from

The espresso martini is a London invention, and its creator is not in doubt: Dick Bradsell, one of the most influential London bartenders of his era. The details are fuzzier.

According to the story Bradsell told, a woman — usually described as a model — came into the Soho Brasserie on Old Compton Street in the 1980s and asked for a drink that would both wake her up and get her drunk. The year is often given as 1983, but his daughter, Beatrice Bradsell, has said he remembered David Bowie's film Absolute Beginners being shot in Soho at the time, which would put it nearer 1985.

The first version was not quite the drink we know. It was a Vodka Espresso: vodka and espresso with a little sugar syrup, served on the rocks with three coffee beans — and no coffee liqueur. By the late 1990s, when it went on the menu at the London bar Match EC1, it was being served in a stemmed glass, and the martini craze of the decade gave it the name that stuck. At Damien Hirst's Notting Hill bar Pharmacy, from 1998, Bradsell briefly renamed it the Pharmaceutical Stimulant.

What is in the glass

Alcohol. Assume a 40% vodka and Kahlúa at 20%, its strength in the United States (it was cut to 16% in the UK and Canada in 2021). The IBA recipe then contains:

• 50 ml × 0.40 = 20 ml of pure alcohol from the vodka
• 30 ml × 0.20 = 6 ml from the Kahlúa

That is 26 ml, or about 20.5 g, of pure alcohol. The US defines a standard drink as 14 g of alcohol, so one espresso martini is about 1.5 standard drinks; in UK units of 10 ml it is about 2.6 units. It is a strong cocktail that tastes like a mild one.

Caffeine. The usual estimate for a single espresso is about 63 mg of caffeine. Kahlúa's maker puts its caffeine at about 100 mg per litre, so 30 ml adds about 3 mg. A single-shot espresso martini therefore carries roughly 65 mg — about two-thirds of a mug of filter coffee — and a double-shot version about twice that. Café espressos vary widely, as the caffeine guide explains.

The combination. The US Centers for Disease Control and Prevention is clear that caffeine does not reduce the effects of alcohol. It can, however, make you feel less affected than you are, which can lead people to drink more. If you are having a second, count the alcohol, not how alert you feel.

Variations worth knowing

• Decaf espresso martini. Made with decaf espresso it carries only a few milligrams of caffeine from the liqueur, which makes it the sensible late-night version — the coffee and sleep guide explains why a late espresso matters.
• Bradsell's original. Vodka, espresso and sugar syrup on the rocks, no liqueur — leaner and more bitter.
• Moka pot version. With no espresso machine, strong moka pot coffee is the usual stand-in. The flavour is close; the head is usually thinner.

For more coffee drinks, alcoholic and not, see the types of coffee drinks guide.