In a bowl, combine the sugar and the grapefruit peel. Press on the peel with a spoon or a muddler to help release the oil. Let macerate for one hour.
To the sugar and grapefruit, add the almond milk. Remove the grapefruit peel (chop-sticks or tweezers work great for this.)
Add the almond extract and orange flower water. Stir to dissolve the sugar. Or place everything in a jar and shake to dissolve the sugar.
Optional - add one ounce of vodka to the syrup before storing in the refrigerator.
Notes
An organic grapefruit is preferred since you are using the peel. Demerara sugar gives a richer flavor, but you may substitute white sugar. This will keep in the fridge for one week, however if you use the optional vodka, it will keep for about a month.