1Combine all of the ingredients in a small saucepan and stir. Place over high heat and bring to a boil. Once the mixture boils, reduce the heat to low and simmer until the rhubarb is falling apart and the color has bled into the syrup, about 20 to 25 minutes.
2Remove from the heat and, using a fine-mesh strainer, strain and discard the rhubarb solids. Let the syrup cool to room temperature, then transfer it to a resealable container and store in the refrigerator for up to 3 weeks.