Combine all ingredients in a saucepan and bring to a boil.
Reduce heat and simmer 20-25 minutes until the rhubarb has fallen apart and the mixture has thickened.
Remove, and allow it to cool to room temperature.
Strain into a glass jar through a very fine mesh strainer while gently pressing the fruit to extract as much of that delicious juice as possible. *Discard the solids or use as a jam.
Store in the refrigerator for several weeks.
Notes
*You can discard the smashed rhubarb solids or use as a jam. Note: Most simple syrup recipes use equal parts water to sugar. I don't like that combination, as I'm not a fan of overly sweet drinks. So most of my simple syrup recipes are 2 parts water to 1 part sugar, as to make a syrup that isn't too sweet. If you like a sweeter drink, then use equal parts water to sugar.