Take your elderberries and water and bring to a boil.
Once boiling drop the heat to a simmer. Simmer the liquid for as long as it takes to reduce to half, around 40 minutes to an hour.
Take it off the heat and pour the liquid and berries through a fine mesh sieve. Use the back of a spatula to squeeze any extra juice out of the berries by pushing on them.
Once the liquid is cooled add your honey and whisk together.