Rinse your rhubarb and cut the ends. Chop the rhubarb into small pieces and place in a large saucepan.
Cover the rhubarb in the saucepan with water and bring to a boil. Immediately reduce the heat and simmer for 20-25 minutes. As it simmers, remove the foam that may rise to the top.
After 20 minutes, the rhubarb should be very mushy, but the rhubarb water should be a pinkish red.
Turn off the heat and pour the rhubarb over a strainer into a second (clean) pot.
Return the rhubarb liquid back to the original pan/pot and add the sugar. Stir to combine, and bring the mixture to a boil. Reduce the heat and allow to simmer for 8-10 minutes until the sugar dissolves.
Remove from the heat and allow to cool; once cool, pour into a jar or bottle and refrigerate.
The syrup will last for 4-5 weeks, once refrigerated.