Dark 'n' Stormy

Wash the lime and cut it into four wedges. use one wedge per cocktail.

Chill the ginger beer and the glasses to keep the cocktail fresh and fizzy.

Fill four highball glasses with four ice cubes each. the ice should reach roughly two-thirds up the glass.

Pour about 150 ml of ginger beer into each glass, leaving space for the rum and any stirring.

Measure 50 ml of dark rum for each glass and slowly pour it over the back of a spoon onto the surface so it forms the characteristic dark 'stormy' layer on top.

Garnish each cocktail with a lime wedge.

If desired, squeeze a little lime juice into the glass and give it one gentle stir.

Serve immediately while the drink is cold and the ginger beer is sparkling.