Wash and dry the lemons, rub the peel and squeeze out the juice so that approx. 500 ml of juice are produced. Peel and quarter the apples, remove the core and grate finely.
Pluck the leaves off the herbs and roughly chop them.
Mix the lemon juice, grated apples, herb leaves, 6 tablespoons of sugar, maple syrup and citric acid in a bowl and stir until the sugar has dissolved.
Pour the fruit mixture through a cheesecloth or juice cloth (place another bowl underneath) and let the juice run off overnight.
Mix the juice obtained with the remaining sugar in a saucepan and cook everything for about 5 minutes until the mixture has become thick. If necessary, skim the whole thing and fill it into sterile bottles while still hot.
Store the whole thing as cool and dark as possible, then the syrup will keep for about a year.