This is a blue Curacao syrup recipe based on the blue Curaçao liquor. It is non-alcoholic and has a delicate, sweet orange flavor with a slightly bitter finish.
Peel the oranges using a vegetable peeler or sharp knife and keep the pith on.
Add the orange peel and sugar to a saucepan. Rub the sugar firmly into the peel for a minute or two to start releasing the oils.
Let the peel and sugar sit for 30 minutes.
Add the water and citric acid or lemon juice. Place over medium heat and bring to a simmer. Simmer for 2 minutes until the sugar is fully dissolved.
Remove from the heat and add 1/2 tsp of non-alcoholic bitters and stir. Let the peel steep as the syrup cools. For the best flavor, transfer to the fridge and steep overnight.
Strain through a muslin cloth or fine mesh sieve into a clean bowl.
Add royal blue gel food coloring a tiny amount at a time, stirring well between each addition, until you reach a deep blue color.
Pour into a clean glass jar. Store in the fridge for up to a month.
Notes
Add 1/2 tsp of non-alcoholic bitters off the heat while the syrup is still warm. Orange or aromatic bitters both work well - I use All the Bitter non-alcoholic bitters. Make sure to use non-alcoholic bitters - most standard bitters contain alcohol which would make this syrup unsuitable for mocktails.
Use royal blue gel food coloring rather than liquid. Liquid food coloring often pulls green in this syrup. Gel gives a true, deep blue without needing much of it.
The syrup will look very dark and intense in the bottle. It lightens significantly when mixed into a drink.
Letting the peel steep overnight in the fridge gives a much more intense orange flavor than just one hour.
Keeps in the fridge in a sealed jar for up to a month. Can be frozen for up to 3 months.