Illegal
The Illegal is a mezcal sour with a rum backbone, and it is one of the drinks that made mezcal make sense to people who thought they disliked it. Thirty millilitres of espadín against fifteen of Jamaican overproof white rum, with falernum, maraschino, lime and a little syrup, and the effect is smoke framed by fruit rather than smoke on its own. The split base is doing the work. Mezcal alone in a sour is austere and can read as ashy; the overproof rum adds ester-heavy fruit and raw power that pushes back against the smoke and gives the drink a middle. Falernum and maraschino then supply spice and a dry cherry note that meet both. It takes its name from a mezcal brand and carries the suggestion of something clandestine, which suits a drink built on a spirit that spent decades as an unregulated village product.
Glassware: Coupe Glass
Garnish:
Ingredients
30ml
The workhorse agave and the right one for mixing: clean roasted-agave smoke with enough fruit underneath to survive five other ingredients. Wild varietals are more distinctive and wasted here, where the falernum and lime would cover what makes them special.
15ml
Unaged and almost pure ester: banana, pineapple and a solvent sharpness with no barrel to soften it. Against the smoke that fruit reads as brightness, and the extra proof carries aromatics that would otherwise sit flat under the lime.
15ml
Lime, almond and clove at around 11 per cent, bridging the mezcal's smoke and the citrus. It comes from the same tiki tradition as the rum, and without it the drink has an audible gap between the base and the lime.
1 bar spoon
A bar spoon is barely a measure and still clearly present: it is one of the most assertive liqueurs behind a bar. Dry cherry and almond rather than sweetness, used exactly as it is in a Last Word.
22.5ml
A full sour measure, squeezed to order. It is the only acid against two sweeteners and a smoky base, and bottled juice announces itself immediately in a drink with this much going on above it.
15ml
One to one, and a smaller measure than a standard sour takes because the falernum is already sweetening. It is here to balance the lime rather than to make the drink sweet, and pushing it higher flattens the smoke.
A few drops, optional
Optional in the official specification, and at a few drops it gives silk rather than a foam. It softens the overproof rum’s edge and gives the drink a rounder texture without turning it into a sour with a head on it.
Instructions
Squeeze the lime immediately before building the drink.
Add the mezcal, overproof rum, falernum, maraschino, lime juice and syrup to a shaker.
Add a few drops of egg white if using, and dry shake for 10 seconds.
Add ice and shake hard for a further 12 seconds.
Double strain into a chilled coupe, or pour over ice in a clay mug.
Source: the IBA (Official IBA specification). Last checked 13 August 2026.
Expert Tip
Keep the rum overproof. Fifteen millilitres sounds like a rounding error next to the mezcal and it is doing structural work: unaged Jamaican rum at high proof is almost pure fruit ester, and that fruit is what stops the smoke reading as ashy. A standard white rum makes a softer, duller drink, and the proof is part of the recipe rather than an accident of what was on the shelf. Measure the maraschino with a bar spoon and no more. It is among the most assertive liqueurs behind any bar, and a jigger of it would erase everything else in the glass. Try it in an unglazed clay mug if you have one. It is the traditional Oaxacan vessel for mezcal, it holds the cold well, and the porous surface does something to the aroma that a coupe does not.
Flavour Profile
Espadín
The specification names espadín specifically, and it is the right call for a mixing mezcal.
Espadín is the workhorse agave: cultivated rather than wild, harvested at six to eight years, and accounting for the large majority of mezcal produced. Wild varietals such as tobalá or tepeztate are rarer, more expensive and more aromatically distinctive, and putting them in a drink with five other ingredients wastes what makes them worth buying. Espadín brings clean roasted-agave smoke with enough fruit underneath to survive the falernum and the lime.
Smoke in mezcal comes from roasting the agave hearts in earth pits over hot rocks before fermentation. It is a production method rather than an additive, which is why it tastes integrated rather than applied.
The Overproof Half
Fifteen millilitres of Jamaican overproof white rum is a small measure of a very loud spirit, and removing it collapses the drink.
Unaged Jamaican rum at overproof strength is almost pure ester: banana, pineapple and a solvent sharpness with no barrel character to soften it. Against mezcal's smoke that fruit reads as brightness rather than sweetness, and the extra alcohol carries aromatics that would otherwise sit flat under the lime. It is the same principle as a float of overproof on a tiki drink, applied structurally rather than on top.
Substituting a standard white rum makes a softer, duller drink. The proof is part of the recipe.
Falernum and Maraschino
Two modifiers in small measures, each meeting a different part of the base.
Falernum brings lime, almond and clove at around 11 per cent — sweet, spiced, and closely related to the tiki tradition the rum comes from. Maraschino brings a dry, faintly bitter cherry-and-almond note at a bar spoon, which is barely a measure and still clearly present; it is one of the most assertive liqueurs on a back bar and it is used here the way it is used in a Last Word.
Between them they cover the gap between smoke and citrus. Take either out and the drink has a hole in the middle.
How to Serve It
Shaken hard and strained into a chilled coupe, or over ice in a clay or terracotta mug.
The specification offers both and the mug is worth trying: unglazed clay is the traditional vessel for mezcal in Oaxaca, it keeps the drink cold, and the porous surface does something subtle to the aroma that glass does not. The few drops of egg white are optional and add a light texture rather than a foam — at that quantity it is silk rather than a head.
Serve it cold and serve it to someone who says they do not like mezcal. It changes minds more reliably than anything else on the list.
The Spirit
MezcalA distilled Mexican spirit made from agave, traditionally cooked in underground pits, giving mezcal its characteristic smoky flavour. Styles range from lightly smoky and herbal to intensely earthy and complex.
Frequently Asked Questions
What is an Illegal cocktail?
A mezcal sour with a split base: 30ml espadín mezcal and 15ml Jamaican overproof white rum, with falernum, a bar spoon of maraschino, lime and simple syrup. Egg white is optional. It is named after the mezcal brand.
Why is there rum in a mezcal cocktail?
To give the smoke something to push against. Mezcal alone in a sour is austere and can read as ashy; unaged overproof Jamaican rum brings fruity esters and raw power that fill the middle of the drink and lift the aromatics.
What is espadín mezcal?
The cultivated workhorse agave behind most mezcal, harvested at six to eight years. It carries clean roasted-agave smoke with fruit underneath, which is what a mixed drink needs. Wild varietals are more distinctive and largely wasted in a six-ingredient cocktail.
Do I need the egg white?
No — the specification marks it optional. At a few drops it gives a silky texture rather than a foam, softening the overproof rum’s edge. Left out, the drink is sharper and slightly more austere, which some people prefer.
Where this one sits
Recipe by Jerry Can Spirits
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