Rhubarb grows in long, tough stalks, and it’s inedible until it’s cooked and softened. This makes it perfect for syrup – simply chop up a few stalks, add ’em to a saucepan along with a couple cups each of sugar and water, bring it all to a boil, and then reduce the heat to a simmer and cook for 15 minutes, stirring ocassionally. When it’s done, you’ll have a deep-pink, sweet-tart syrup that brings an unmatched vernality to cocktails.