Put blueberries and water in a saucepan over medium heat. Simmer the berries for five minutes then remove from the heat.

Use a fork to mash all of the blueberries into a purée.

Strain the blueberry purée through a cheesecloth. You will be left with highly pigmented blueberry juice.

Return the blueberry juice to the saucepan. Simmer, stirring constantly, until it has reduced into the consistency of a thick syrup. Be careful to not burn it.

Pour the blueberry syrup into a bowl with the kosher salt. Use a rubber spatula to work the syrup into the salt until the grains are evenly coated and colourful.

Spread the blueberry salt on a parchment paper covered tray and allow to dry for twenty-four hours.