Combine water and sugar over low heat and stir until the sugar completely dissolves, then allow to cool
Bring a second pot of water to a rapid boil. Dip the mint into the boiling water for 15 seconds, and then immediately submerge in ice water for 1 minute
Remove stems from the cooled mint, if any, and blend the simple syrup and mint leaves at high speed for 1 minute
Strain through a fine-mesh strainer or cheesecloth and refrigerate