Always discard rhubarb leaves as they are toxic. Leave the skin on the stalks for the best bright pink color. For a smoother texture, blend the finished sauce. Add strawberries, orange zest, vanilla, or ginger for delicious variations. Store refrigerated for up to 2 weeks or freeze for up to 6 months. For canning, process sterilized jars in a boiling water bath for 15 minutes.