If using fresh elderflowers, wash them and pat them dry.
In a medium saucepan over medium heat, bring the elderflowers and water to a simmer. Reduce the heat to medium-low and cook for 20 minutes. The liquid will reduce.
Place a fine-mesh strainer over a large bowl and strain the tea mixture to yield a smooth, refined liquid. Strain again if any seeds or floral bits come through. Discard the spent elderflowers.
Measure the hot liquid and add an equal amount of sugar. (Alternatively, measure 1 cup of liquid and 1 cup of syrup.) Stir until dissolved.
Let cool completely, then funnel the elderflower syrup into an airtight jar or bottle. Use immediately or store in the fridge for up to one month.
Elderflower Gin Cocktail
In a cocktail shaker filled with ice, combine gin, elderflower syrup and lemon juice.
Shake well and strain into a cocktail glass. (The drink can be served neat in a coupe glass or on the rocks in an old-fashioned glass.)
Garnish with a slice of lemon.
Notes
This drink can be served neat in a coupe glass or on the rocks in an old-fashioned glass.