Remove the tops, leaves and ends, taking care to dispose of the leaves in a safe place.
Chop into 1-inch pieces.
Set up a bowl full of ice water. Place a clean kitchen towel unfolded and flat on the counter.
Bring a pot of water to a rolling boil.
Add rhubarb to the boiling water and boil for 1 minute.
Once the time is up, strain the rhubarb through a colander or scoop pieces out of the water with a slotted spoon and immediately add to the ice water for two minutes.
Strain again and set aside to drain.
Spread out on the clean towel and blot dry.
How to Freeze Rhubarb
If you're not blanching, you'll still follow steps 1-3 above.
Line a rimmed baking sheet with parchment or a silpat.
Add chopped rhubarb to the baking sheet without crowding the tray and place the tray in the freezer.
Freeze for three hours.
Break apart any clumps that have formed on the baking sheet and transfer to freezer-proof storage.
Notes
There is no need to thaw before adding to dishes.Store unblanched in the freezer for up to two months, or blanched for up to 12 months.