Wash the rhubarb under cold water, trimming off the leaves and tough ends. Discard the leaves, as they are toxic.
Slice the rhubarb in 1-inch pieces (or your preferred size.)
Prepare a large bowl of ice water and set aside.
Bring a large pot of water to a rolling boil, using four quarts of water for each pound of rhubarb.
Add the rhubarb to the boiling water and cook for one minute. Immediately strain the rhubarb and add to the ice water bath. Let it sit in the ice water for several minutes to stop the cooking process, then drain thoroughly on paper towels.
Spread the rhubarb pieces in a single layer on a baking sheet lined with parchment paper. Freeze for two hours, or until firm.
Transfer the frozen rhubarb to an airtight freezer bag or container. Label with the date and store for up to 6 months.
Notes
To Thaw Frozen Rhubarb: For best results, transfer it to the refrigerator and allow it to gradually thaw overnight. Alternately, you can thaw it at room temperature for several hours or use the defrost feature in your microwave. Before using the rhubarb, drain off any excess liquid that may have accumulated during thawing.