Infusing simple syrup with other flavors is pretty common. Here is Dr. Cocktail’s recipe for Pineapple Syrup:
- 4 cups cane sugar
- 2 cups water
- 1 small fresh pineapple, skinned and cubed
Stir all ingredients together. Let stand for 24 hours. Remove the pineapple cubes, lightly pressing them with a hand juicer or other method to squeeze some additional juice into the mixture. Stir to dissolve any residual sugar. Pour the resulting syrup through a tea strainer or cheesecloth-lined funnel into a 1.5 liter bottle. Add a small dash of spirits (any distillate of at least 80 proof; 151 rum recommended) as a preservative. Keep refrigerated. It should keep for three months easily.
This is a 2:1 ratio simple syrup – on the sweet side (it can go as low as 1:1). Although not specified, I heated the sugar and water long enough to get the sugar to dissolve.