Try a subscription
You first 5 issues for only £5 and never miss our best recipes
Tip the gin, lemon juice, sugar syrup and egg white into a cocktail shaker. Shake well until frothy, then add a large handful of ice and shake again until the outside of the shaker feels cold.
Double-strain into a tall glass filled with some more ice, then top up with the sparkling water. Thread a blackberry onto a cocktail stick to use as a garnish, or top with a thyme sprig.
Comments, questions and tips