Wash the green grapes after detaching them from the stems.

Place the green grapes in a bowl.

Detach the black grapes from the stems and wash them.

Cut each black grape in half.

Remove the seeds from each grape half using a bent paper clip.

Place the cleaned black grape halves in the bowl with the green grapes, ensuring no seeds remain.

Add the grated lemon zest to the bowl.

Add the sugar to the bowl.

Strain the orange juice over the grapes.

Stir the mixture well.

Cover the bowl and chill for two hours before serving.