How to Freeze Rhubarb

By Mark Heidelberger

Rhubarb has long been a preferred ingredient in crumbles, pies, cakes and jams because its tangy tartness balances well with the saccharine taste of sugar. While this crimson-stalked veggie is typically harvested in springtime, many people wish to store it for use in later seasons. Freezing is not only a safe method for preserving fresh rhubarb, but is also the most effective so long as it's done properly.

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Choosing the Right Container

Freezer Bags

Sealable plastic bags are a viable option only when the rhubarb is dry. Using them for rhubarb packed in liquid leaves too much potential for mess. The flexibility of the bags also means you can conserve room in your freezer. Once the rhubarb is placed inside, you will need to make sure that all of the air is completely squeezed out of the bag before sealing it.

Rigid Containers

Hard plastic storage containers are best when liquid is involved, although they can effectively store dry rhubarb, too. Be sure the container is freezer safe and has a tight-fitting lid to guard against freezer burn. Also, buy rectangular containers instead of round ones for the most economical use of freezer space.

Preparing the Rhubarb

Selection

Only freeze fresh, high-quality rhubarb. The stalks should be firm, crisp and free of blemishes. Any excess stringy fibers should be removed. When ripe and healthy, the stalks will also have an even dark red color -- or green, depending on the variety -- from top to bottom.

Washing

Thoroughly clean the rhubarb prior to freezing it by placing each stalk under cold or lukewarm running water, and gently rubbing off any dirt with your fingers.

Cutting

Cut off the ends of the rhubarb, and then chop the stalk into whatever size and shape you desire for your end product. Half-inch pieces are a solid size for use in pies and crumbles. If your chosen variety of rhubarb has a tough outer skin, peel it off prior to cutting.

Blanching

Blanching is an optional step used to preserve color and flavor. It is most effective for rhubarb that will be frozen for more than two months. Place the sliced pieces of rhubarb in a colander and submerge them in a pot of boiling water for 1 minute. Promptly remove them, and then submerge them in a pot of ice cold water for 3 to 4 minutes. Finally, place the pieces on paper towels in a single layer and allow them to dry thoroughly.

Freezing Methods

Dry Pack

Spread the rhubarb pieces out in a single layer on a baking sheet and place uncovered in the freezer. After 2 hours, remove the rhubarb from the baking sheet and place in an airtight freezer bag or plastic container. Allow at least 1/2 inch of head space for additional expansion during the freezing process. Then place the containers back inside the freezer.

Wet Pack

This process involves packing the rhubarb in a solution of water and sugar or fruit juice, which stabilizes color, enhances flavor, wards off freezer burn and maintains the stalk's shape. Use 1/2 cup of sugar for each full cup of water. You need just enough solution to cover your pieces; typically 1 cup of solution per quart of rhubarb. Heat the water in a pot over the stove while slowly stirring in the sugar. Once the sugar has dissolved, remove the pot from the heat and allow it to cool for 30 minutes. Mix the solution thoroughly with the rhubarb, ladle it into your container, seal it and place it in the freezer.

Pie Filling

Pre-made rhubarb pie filling should be cool prior to freezing. Pre-measure the amount you will need for your pie. Add 1/2 teaspoon of ascorbic acid if desired to preserve color and resist oxidation. You may also add 1/2 teaspoon of tapioca or modified food starch to maintain consistency and prevent boiling over when it is eventually baked. Ladle the filling into a large freezer bag, ensuring all the air has been removed, and then place it in the baking pan you plan to use. Shape the bag to fit the pan, and then place both in the freezer. Once the bag is frozen, remove the pan. When the filling is ready to be used, simply remove the bag and shape the pie crust around the frozen filling.

Tips

  • Use freezer tape to mark your containers with the contents, quantity and date of freezing.
  • Freezing the rhubarb pieces on a baking sheet prior to placing them in a container makes it easier to remove small quantities at a time, as they will not stick together.
  • A vacuum sealer is a dependable way to ensure all air is removed from your storage bags. If you don't have one, try using a straw to suck excess air out.
  • Natural peach, apple and white grape juice serve as effective wet pack solutions and are ideal if you want to avoid processed sugar.