6 cups water
1 1/4 cup caster sugar
1 bunch thyme
8 sprigs thyme
Cut the lemon and limes in half and juice 6 lemons and 6 limes. Slice the remaining limes and lemons and place in an heatproof pitcher or container.
Combine the lime juice, lemon juice, thyme bunch, water and sugar, and cook over low heat in a large sauce pan until the sugar dissolves. Pour the mixture over the sliced citrus in your heatproof container. Cover with plastic wrap and allow to chill for three hours.
Divide the crushed ice and pour the lemon and limeade mixture over serving with a fresh thyme sprig.