Gently rinse the elderflower heads to remove any dirt or insects without damaging the blossoms.

In a large glass jar, layer the elderflower heads, lemon zest, and juice, then pour the vodka to fully submerge the flowers.

Seal the jar tightly and store in a cool, dark place for 2-3 days to allow the flavors to infuse.

In a saucepan over medium heat, combine the water and sugar, stirring until the sugar dissolves completely (about 5-7 minutes), then let the syrup cool.

After infusion, strain the mixture through a fine mesh strainer or cheesecloth into a clean bowl to remove flowers and sediment.

Combine the cooled sugar syrup with the strained elderflower infusion, taste, and adjust sweetness as needed.

Using a funnel, pour the liqueur into clean glass bottles, seal tightly, and label with the date.

Let the bottled liqueur mature for at least one week before serving for best flavor.