Pare the zest from all the lemons, taking care not to include any white pith. Put the zest in a large clean jar and pour over the vodka. Cover with a tightly fitting lid and leave for a week, shaking the jar each day.
Put the sugar in a heatproof bowl and pour over the boiling water, stirring until the sugar has dissolved. Add the vodka and peels and leave for a further week, shaking the jar regularly.
Strain into decorative bottles, adding a few strips of lemon zest to each bottle.