In a small sauce pan over medium-high heat, bring water to a boil.
Reduce to medium heat and add granulated sugar to the water and stir constantly until fully dissolved.
Add dark brown sugar to the saucepan and stir constantly until fully dissolved.
Return heat to medium-high and stir syrup constantly until syrup boils.
Reduce heat to low and simmer for 5 minutes. Stir in maple extract. Serve warm or store for later use.
Notes
This is a very basic simple syrup recipe and was tested it many times and this method to make homemade syrup has proven not to crystallize. Crystallization occurs when sugars do not completely dissolve and the instructions involve constant stirring until sugars have completely dissolved. If there are any granules of sugar that do not dissolve, the sugar molecules will begin to attract other molecules and form crystals.